Full opinion text
MEMORANDUM OPINION RANDOLPH D. MOSS, United States District Judge The Department of the Interior undeniably has the authority to prohibit the importation of species of wild animals deemed by the Congress or the Department to be injurious to human beings, agriculture, horticulture, forestry or other wildlife. This case presents the question whether Congress has also authorized the Interior Department to ban the interstate transportation of these “injurious species.” The case addresses, in particular, whether the Department acted within its authority when it issued regulations purporting to prohibit the interstate transportation of certain species of large constricting snakes, including the reticulated python, which can grow to over 20 feet in length, and the green anaconda, which is almost certainly the heaviest snake in the world. Ultimately, however, the scope of the Interior Department’s authority to regulate the interstate transportation of “injurious species” depends on the history of the zebra mussel, which is a mollusk about the size of a quarter, and the bighead carp, which is a freshwater fish with a voracious appetite. For the reasons explained below, Defendants have failed to. establish at this point in the litigation that this history is sufficient to confer an authority on the Department that Congress did not confer when it enacted the controlling statutory text. Before the Court is Plaintiffs’ motion for a preliminary injunction (Dkt.28). Plaintiffs seek an order enjoining the Secretary of the Interior, Sally Jewell, and the U.S. Fish and Wildlife Service (collectively, “Defendants”) from implementing the final rule promulgated on March 10, 2015, which adds four species of constricting snakes to the list of injurious species under the Lacey Act, 18 U.S.C. § 42. A hearing on the motion was held on April 7, 2015, and, upon consideration of the parties’ arguments and submissions, and for the reasons explained below, the motion is GRANTED in part and a preliminary injunction will issue. In light of the requirement that injunctive relief be “narrowly tailored to remedy the specific harm shown,” Neb. Dep’t of Health & Human Servs. v. Dep’t of Health & Human Servs., 435 F.3d 326, 330 (D.C.Cir.2006), the parties are ORDERED to submit supplemental briefs on the proper scope of the injunction and whether a brief stay is appropriate. The parties are further ORDERED to appear for a status conference on May 18, 2015 at 10:00 AM to address the scope of the injunction. The Court will issue a preliminary injunction after hearing from the parties regarding its proper scope. BACKGROUND This action challenges rules promulgated by the Department of the Interior (“Department”) that prohibit the importation and interstate transportation of certain species of constricting snakes. In 2010, the Department proposed a rule listing nine constricting snake species as “injurious” under the Lacey Act, 18 U.S.C. § 42. See 75 Fed.Reg. 11808 (March 12, 2010). When the Secretary of the Interior designates a species as “injurious to human beings, ... agriculture, horticulture, forestry, or ... wildlife or the wildlife resources of the United States,” the Lacey Act prohibits “importation” of that species “into the United States, any territory of the United States, the District of Columbia, the Commonwealth of Puerto Rico, or any possession of the United States.” 18 U.S.C. § 42(a)(1). It also prohibits “any shipment” of the species “between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States.” Id. On January 23, 2012, after a notice and comment period, the Department issued a final rule listing four of the nine species as “injurious.” 77 Fed.Reg. 3330 (Jan. 23, 2012) (the “2012 Rule”). The rule prohibited “the importation into the United States and interstate transportation between States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States of any live animal, gamete, viable egg, or hybrid” of those four snakes. Id. The United States Association of Reptile' Keepers (“USARK”) filed this lawsuit on December 18, 2013. On May 9, 2014, with leave of the Court, USARK filed an amended complaint alleging (1) that the ban on interstate transportation of listed species in the 2012 Rule exceeded the Interior Department’s powers under the Lacey Act (Dkt. 21 ¶¶ 78-84); (2) that the 2012 Rule failed to comply with the requirements of the National Environmental Policy Act (“NEPA”) (Dkt. 21 ¶¶ 85-94); and (3) that in promulgating the 2012 Rule the Department of the Interior abused its discretion and acted arbitrarily and capriciously (Dkt. 21 ¶¶ 95-97). Defendants moved to dismiss the amended complaint (Dkt.22). On March 10, 2015, the Interior Department promulgated another final rule listing four additional constricting snake species — the reticulated ■ python, DeSchauensee’s anaconda, green anaconda, and Beni anaconda — as “injurious.” 80 Fed.Reg. 12702 (Mar. 10, 2015) (the “2015 Rule”). Like the 2012 Rule, the 2015 Rule prohibited both “importation” and “interstate transportation between States” of the newly listed species. Id. It explained that two of the listed species — the reticulated python and the green anaconda — were among the “largest snakes in the world”; that both were already “present in U.S. trade”; and that examples of both “ha[d] been found in the wild in south Florida.” Id. at 12704. The Department was chastened by its experience with the Burmese python, which it cited as an “example of a species that may not have become so invasive in Florida if it had been listed before it had become established.” Id. And it noted that the listed snakes were “highly likely to prey on U.S. native species” and, if introduced into the wild, would rank among the most powerful predators in North America. Id. at 12713 (reticulated python); see id. at 12716-17 (green anaconda). The 2015 Rule took effect on April 9, 2015-30 days after the final rule was published. USARK moved for leave to file a Second Amended Complaint on March 23, 2015. Dkt. 27. The Second Amended Complaint challenges both the 2012 and 2015 Rules. In addition to the arguments raised in the First Amended Complaint, it alleges that the Rules’ prohibition on interstate transportation of listed snakes impermissibly burdens snake owners’ constitutional right to travel (Dkt. 38 ¶¶ 109-117) and that the Interior Department failed to satisfy the requirements of the Regulatory Flexibility Act, 5 U.S.C. § 601 et seq. (Dkt. 27-1 ¶¶ 131-135). The Second Amended Complaint also adds four individual plaintiffs, all qf whom allege that they will be harmed by one or both of the challenged Rules. Dkt. 38 ¶¶ 13-16. The Court granted the motion for leave to amend on April 8, 2015. Dkt. 37. On April 1, 2015, Plaintiffs filed an Application for Temporary Restraining Order. Dkt. 28 (“TRO Application”). The TRO Application sought to enjoin implementation of the 2015 Rule. Plaintiffs argued that they are likely to prevail on the merits based on their statutory construction and Regulatory Flexibility Act arguments. They further argued that the individual plaintiffs and members of USARK will suffer irreparable harm if the 2015 Rule takes effect. The TRO Application addressed only the reticulated python and green anaconda; Plaintiffs acknowledge that “[t]he other two species” listed in the 2015 Rule, “the Beni and DeSchauensee’s anaconda, are not even found in the United States, in trade or otherwise.” Id. at 4. Thus, Plaintiffs have not requested that the Court enjoin' application of the 2015 Rule as to those snakes (and it is unlikely Plaintiffs would have standing to do so). After briefing on the TRO Application, the Court held a hearing on the application. At the hearing, the parties agreed the TRO Application could be treated as a motion for a preliminary injunction; accordingly, the Court denied the request for immediate relief and ordered the parties to submit supplemental briefing on a number of issues. See Dkt. 37; Dkts. 44, 45, 48, 49. The motion for a preliminary injunction is now before the Court. LEGAL STANDARD To prevail on a motion for a preliminary injunction, the party seeking relief must show “(1) a substantial likelihood of success on the merits; (2) that the moving party would suffer irreparable injury if the relief were not granted; (3) that the balance of equities tips in the movant’s favor; and (4) that an injunction is in the public interest.” EDF Res. Capital, Inc. v. U.S. Small Bus. Admin., 910 F.Supp,2d 280, 283 (D.D.C.2012) (citing Chaplaincy of Full Gospel Churches v. England, 454 F.3d 290, 297 (D.C.Cir.2006)). The Court of Appeals for this Circuit long evaluated these factors on a “sliding scale.” E.g., Davenport v. Int’l Bhd. of Teamsters, AFL-CIO, 166 F.3d 356, 360-61 (D.C.Cir. 1999). It has recently read the Supreme Court’s decision in Winter v. Natural Resources Defense Council, Inc., 555 U.S. 7, 129 S.Ct. 365, 172 L.Ed.2d 249 (2008), however, “at least to suggest if not to hold” that plaintiffs face “a more demanding burden” under which “a likelihood of success is an independent, freestanding requirement for a preliminary injunction,” Sherley v. Sebelius, 644 F.3d 388, 392-93 (D.C.Cir.2011) (quotation marks omitted). This issue remains the subject of some uncertainty in this Circuit. See Am. Meat Inst v. U.S. Dep’t of Agric., 746 F.3d 1065, 1074 (D.C.Cir.2014), reinstated in relevant part by 760 F.3d 18 (D.C.Cir.2014) (en banc) (“[t]his circuit has repeatedly declined to take sides ... on the question of whether likelihood of success on the merits is a freestanding threshold requirement to issuance of a preliminary injunction”). Nonetheless, it is clear that the plaintiffs likelihood of success on the merits is a “key issue [and] often the dispositive one” at the preliminary injunction stage. Greater New Orleans Fair Hous. Action Ctr. v. U.S. Dep’t of Hous. & Urban Dev., 639 F.3d 1078, 1083 (D.C.Cir.2011). At a minimum, where movants make “a weak showing on the first factor,” they need “to show that all three of the other factors so much favor the [movants] that they need only have raised a serious legal question on the merits.” Am. Meat Inst., 746 F.3d at 1074 (quotation marks omitted). DISCUSSION I. Likelihood of Success on the Merits Plaintiffs rely on their statutory construction and Regulatory Flexibility Act claims in their attempt to show that they are likely to succeed on the merits. Because the Court concludes that there is a substantial likelihood that Plaintiffs will prevail . on their statutory construction claim, Plaintiffs have satisfied this prong of the preliminary injunction test. A. Plaintiffs’ Statutory Construction Claim, The crux of Plaintiffs’ statutory construction claim is their contention that, with the exception of Hawaii, the Lacey Act does not prohibit interstate shipment of species listed as “injurious” by the Department of the Interior. Defendants dispute this contention, and further argue that Plaintiffs’ claim is barred by the applicable statute of limitations. 1. The Statute of Limitations Defendants argue, as a threshold matter, that the Court lacks jurisdiction to review Plaintiffs’ statutory construction claim because that claim is time-barred under the six-year statute of limitations in 28 U.S.C. § 2401(a). They claim that, although the preamble to the 2015 Rule states that the Rule’s effect is to prohibit interstate transport of the four listed species, the prohibition actually stems from the Interior Department’s 1965 Lacey Act regulations (50 C.F.R. § 16.3; the “1965 Regulations”). They reason that because the 1965 Regulations prohibited interstate transportation of listed species, and the 2015 Rule simply listed the four species at issue here, any claim challenging the prohibition on interstate transportation of listed species accrued in 1965 and must have been brought before 1971. This argument has a serious flaw. The 1965 Regulations do not “interpret” the Lacey Act’s language governing transportation of listed species within the territory of the United States; they simply copy the relevant language. Compare 50 C.F.R. § 16.3 (“the transportation of live wildlife or eggs thereof between the continental-United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any territory or possession of the United States by any means whatsoever, is prohibited ...”) with 18 U.S.C. § 42(a)(1) (“any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States ... is hereby prohibited”). Plaintiffs’ claim challenging Defendants’ interpretation of the Lacey Act cannot have accrued when the Department promulgated regulations merely repeating the relevant language of the statute. As a fallback position, Defendants argue that Plaintiffs’ claim accrued either when the Department first interpreted the Lacey Act to bar interstate transportation of a listed species (1989) or when the Fish and Wildlife Service first issued a rule purporting to bar interstate transportation of a reptile species (1990) — ostensibly the first point at which USARK might have had organizational standing to challenge the rule. See 54 Fed.Reg. 22286, 22,287 (May 28, 1989); 55 Fed.Reg. 17439, 17440 (Apr. 25,1990). Defendants offer no convincing reason to treat these prior rules, rather than the 2012 and 2015 Rules, as the agency actions triggering the running of the limitation period under § 2401. The limitation period under § 2401 begins to run on the date of the “final agency action,” Harris v. FAA, 353 F.3d 1006, 1010 (D.C.Cir.2004), which the Court of Appeals defines as “one by which rights or obligations have been determined or from which legal consequences will flow,” Mendoza v. Perez, 754 F.3d 1002, 1018 (D.C.Cir.2014) (quotation marks omitted). “[A]n agency’s renewal of an earlier decision [that] does not alter the status quo,” however, will not “restart the statute of limitations.” Mendoza, 754 F.3d at 1018. The question, then, is whether the 2012 and 2015 Rules were final agency actions that altered the status quo. Plainly, they were. The Rules determined the rights of persons in the United States to transport animals of the listed species domestically and internationally, and the restrictions they imposed did not exist before the final Rules took effect. A plaintiff who could lawfully transport reticulated pythons or green anacondas across state lines in 2009 now cannot do so. The agency’s actions that made that so triggered the start of the .six-year limitation period here. See id. at 1019 (holding that regulations that had “long existed” as to shepherds and goatherds re-started the limitation period when they were extended to reach cattle herders). Moreover, if a rule targeting a different species could start the limitation period under these circumstances, the Interior Department could easily avoid facial review of new statutory interpretations. The Department could simply announce a new interpretation with respect to a listed species not present in the United States (like, for example, the Beni or DeSchauen-see’s anacondas), allow the six-year limitation period to run, and then promulgate new rules applying that interpretation to far more popular species. There is no suggestion, of course, that the Department has intentionally pursued such a strategy here, but the effect of its limitation argument is to cut off a presumptively available avenue for judicial review. See Abbott Labs. v. Gardner, 387 U.S. 136, 140, 87 S.Ct. 1507, 18 L.Ed.2d 681 (1967) (“judicial review of a final agency action by an aggrieved person will not be cut off unless there is persuasive reason to believe that such was the purpose of Congress”). Nothing in the language of § 2401 compels the conclusion that Congress intended to bar facial challenges to rules that extend previous agency interpretations to reach new spheres of previously unregulated activity. Finally, the Court notes that even were Defendants correct that the final agency action establishing the Interior Department’s interpretation of the relevant statutory language took place more than six years before Plaintiffs brought suit, the Department’s subsequent actions would render this lawsuit timely because the Department re-opened the issue. “[A]n agency has reopened a previously decided issue in a case where the agency (1) proposed to make some change in its rules or policies, (2) called for comments only on new or changed provisions, but at the same time (3) explained the unchanged, republished portions, and (4) responded to at least one comment aimed at the previously decided issue.” Public Citizen v. NRC, 901 F.2d 147, 150 (D.C.Cir.1990). Here, the Department clearly “proposed to make some change in its rules or policies” when it issued its proposed rule in 2010. See 75 Fed.Reg. 11808 (Mar 12, 2010). The proposed rule “called for comments” on the listing of constrictor species under the Lacey Act. See id. at 11811. It “explained the unchanged” interpretation of the Lacey Act that Plaintiffs now challenge. See id. at 11808 (“The proposed rule, if made final, would also prohibit any interstate transportation of live snakes, gametes, viable eggs, or hybrids of the nine species currently held in the United States.”). And the Department “responded to at least one comment aimed at” that issue. 80 Fed.Reg. 12702, 12732 (Mar. 10, 2015) (“Comment: ... The Service lacks the authority to restrict interstate transportation and commerce of a listed species between and among continental States. Our response: The Service interprets the Lacey Act as giving us the authority to restrict transportation between any of the States, territories, and other jurisdictions (the District of Columbia) of the United States. We believe that this interpretation is consistent with the language and intent of the statute.”). Because the final agency action at issue was the promulgation of the 2015 Rule, and, in any event, that Rule re-opened the question whether the Department’s interpretation of the relevant Lacey Act provision is correct, this suit was timely filed. 2. Interpretation of the Lacey Act Plaintiffs allege that, by prohibiting interstate transportation of listed snakes, the 2012 and 2015 Rules exceed the authority granted to the Secretary under the Lacey Act. The relevant statutory language states: The importation into the United States, any territory of the United States, the District of Columbia, the Commonwealth of Puerto Rico, or any possession of the United States, or any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States, of [certain enumerated species] and such other species of wild mammals, wild birds, fish (including mollusks and Crustacea), amphibians, reptiles, brown tree snakes, or the offspring or eggs of any of the foregoing which the Secretary of the Interi- or may prescribe by regulation to be injurious to human beings, to the interests of agriculture, horticulture, forestry, or to wildlife or the wildlife resources of the United States, is hereby prohibited. 18 U.S.C. § 42(a)(1) (emphasis added). Plaintiffs argue that the phrase “any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States” does not encompass transportation of listed species between two states within the “continental United States” — thus, in their view, the Interior Department lacked authority to prohibit all interstate transportation of the four species at issue in the 2015 Rule. Plaintiffs contend that the language and legislative history of the 1960 amendments unambiguously show that Congress “expressly intended to limit” transportation of listed species “only between all forty-nine continental states as a singular entity and the other listed jurisdictions (or between those jurisdictions), not within or between the continental states.” Dkt. 28-1 at 20. In response, Defendants argue that the Interior Department interpretation is compelled by the plain language of the statute and bolstered by subsequent congressional actions, and, in the alternative, that it is entitled to deference under Chevron, U.S.A. v. Natural Resources Defense Council, 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). a. Chevron U.S.A. v. Natural Resources Defense Council Under the framework set out in Chevron, a court reviewing an agency’s interpretation of a statute first asks “whether Congress has directly spoken to the precise question at issue.” 467 U.S. at 842, 104 S.Ct. 2778. “If the intent of Congress is clear, that is the end of the matter.” Id. However, if “Congress has not directly addressed the precise question at issue ... the question for the court is whether the agency’s answer is based on a permissible construction of the statute.” Id. at 843, 104 S.Ct. 2778. The principle in Chevron is “rooted in a background presumption ... ‘that Congress, when it left ambiguity in a statute’ administered by an agency, ‘understood that the ambiguity would be resolved, first and foremost, by the agency, and desired the agency (rather than the courts) to possess whatever degree of discretion the ambiguity allows.’ ” City of Arlington, Tex. v. FCC, — U.S. — -, 133 S.Ct. 1863, 1868, — L.Ed.2d-(2013) (quoting Smiley v. Citibank (S.D.), N.A., 517 U.S. 735, 740-41, 116 S.Ct. 1730, 135 L.Ed.2d 25 (1996)). There is significant reason to doubt, however, whether Chevron applies in this context. The Lacey Act is a criminal statute, see 18 U.S.C. § 42(b) (“Whoever violates this section, or any regulation issued pursuant thereto, shall be fined under this title or imprisoned not more than six months, or both.”), and the Supreme Court recently observed that it “ha[s] never held that the Government’s reading of a criminal statute is entitled to any deference,” United States v. Apel, — U.S. -, 134 S.Ct. 1144, 1151, 186 L.Ed.2d 75 (2014). Instead, “[wjhether the Government interprets a criminal statute too broadly ... or too narrowly ... a court has an obligation to correct its error.” Abramski v. United States, — U.S.-, 134 S.Ct. 2259, 2274, 189 L.Ed.2d 262 (2014) (“We think [the agency’s] old position is no more relevant than its current one- — which is to say, not relevant at all.”). This principle is particularly important where, as here, the government advances an “expansive view” of the scope of activities that will subject citizens to criminal penalties. Whitman v. United States, — U.S.-, 135 S.Ct. 352, 353, 190 L.Ed.2d 381 (2014) (Scalia, J., respecting the denial of certiorari). Deferring to such a view would “upend ordinary principles of interpretation,” including the “rule of lenity[, which] requires interpreters to resolve ambiguity in criminal laws in favor of defendants.” Id. In sum, recent Supreme Court authority suggests that “criminal laws are for courts, not for the Government, to construe.” Abramski, 134 S.Ct. at 2274. The Court of Appeals has not yet addressed the Supreme Court’s recent statements suggesting that Chevron deference does not apply to agency interpretations of criminal statutes. On at least two occasions before the Supreme Court’s decision in Apel and Abramski, it did apply Chevron to agency interpretations of statutes that imposed criminal penalties. See United States v. Kanchanalak, 192 F.3d 1037, 1047 (D.C.Cir.1999) (in a criminal case, applying Chevron and deferring to FEC’s interpretation of statute regulating foreign soft money contributions); In re Sealed Case, 223 F.3d 775, 780 (D.C.Cir.2000) (in a criminal case, applying Chevron deference to reject statutory interpretation that had been rejected by the FEC). Although it is not clear. whether the Court of Appeals would follow this practice after Apel and Abramski, there is no need to reach that question here. Rather, as explained below, the Court concludes that, when Congress amended the Lacey Act in 1960, it did not leave an ambiguity or gap for the Interior Department to fill on the fundamental question whether the Act applies to all interstate shipments of listed species or merely shipments between the continental United States and other portions of the territorial United States. Thus, regardless whether Chevron applies, Plaintiffs have demonstrated a likelihood of success on this claim. b. Plain Meaning of the Statute Whether proceeding under Chevron or not, the Court must “exhaust the traditional tools of statutory construction to determine” the plain language of the statute, including “examination of the statute’s text, legislative history, and structure, as well as its purpose.” Petit v. U.S. Dept. of Educ., 675 F.3d 769, 781 (D.C.Cir.2012) (quotation marks omitted). This inquiry “begins where all such inquiries must begin: with the language of the statute itself.” United States v. Ron Pair Enters., Inc., 489 U.S. 235, 241, 109 S.Ct. 1026, 103 L.Ed.2d 290 (1989). Here, the statutory phrase “any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States” does not, standing alone, compel either side’s interpretation. The jarring juxtaposition of “between” and “or” renders the whole statement grammatically confounding, and neither party’s plain-language argument settles the question. Plaintiffs, for example, could make a strong case that the statute targeted only the spread of invasive species between “the continental United States” and its insular state and territories — areas whose unique biodiversity could be threatened by imports from “the continental United States,” and vice-versa. In this view, the “continental United States” is a single, undifferentiated entity — the portion of the United States located on the North American continent. On this reading, though, the separate inclusion of the District of Columbia is baffling. It is unclear why transportation of injurious species between Maryland and the District would merit prohibition while transportation of the same species from Maryland to Virginia could persist unabated. And although Plaintiffs point to other statutes referring to transportation “between the continental United States and ” other locales, see Dkt. 45 at 5, these statutes shed little light on the proper interpretation of the perplexing “between ... or” construction in the Lacey Act. Defendants’ interpretation, on the other hand, treats the “continental United States” as a set of separate entities between which transportation may be prohibited. This interpretation avoids the problems noted above, but creates difficulties of its own. Congress could easily have used much clearer language if it wished to bar all interstate transportation of listed species. And, even though Hawaii had only recently become a State, it is puzzling that in 1960, Congress listed the “continental United States” and Hawaii separately, rather than simply referring to transportation between the “States.” The problem with Defendants’ position is heightened by the fact that Congress used very different language to prohibit the interstate transportation of certain wildlife species in another provision of the 1960 Lacey Act amendments. Amending former 18 U.S.C. § 43 — now codified at 16 U.S.C. § 3372 — Congress replaced the phrase “whoever delivers or knowingly receives for shipment, transportation, or carriage in interstate or foreign commerce” with the following formulation: Whoever delivers, carries, transports, ships, by any means whatever, or knowingly receives for shipment, to or from any State, territory, the District of Columbia, the Commonwealth of Puerto Rico, any possession of the United States, or any foreign country [.] Pub.L. 86-702 (1960) (emphasis added); see Dkt. 31-1 at 13-14. The clear language used to prohibit interstate shipment of listed species under former § 43 strongly suggests that Congress did not intend the prohibition on shipments under § 42 to reach as broadly as Defendants contend. On balance, Plaintiffs thus offer the slightly better reading of the text. Still, in light of the difficulties plaguing both proffered interpretations, the Court concludes that the language of the statute, standing alone, does not conclusively foreclose either of the interpretations advanced here. Because the language of the Lacey Act does not compel either side’s interpretation, the Court looks to the statute’s legislative history to determine its plain meaning. See Petit, 675 F.3d at 781. In this case, the legislative history of the 1960 Lacey Act amendments unambiguously supports Plaintiffs’ position. The 1960 amendments to the Lacey Act were drafted by the Department of the Interior and forwarded to Congress in early 1960. Dkt. 31-1 at 40. Prior to the 1960 amendments, the Lacey Act prohibited “importation into the United States or any Territory or district thereof’ of listed species, but did not address their domestic transportation. See Dkt. 31-1 at 6. A Department of the Interior witness who testified before a subcommittee of the House Judiciary Committee regarding the proposed amendments spoke directly to the purpose of the proposed language: Mr. Parker.... And we have broadened the language a bit to prohibit the shipment between the Continental United States and Hawaii, Puerto Rico, and the Virgin Islands of the Mongoose, for this reason: Currently, the Mongoose occurs in Hawaii, Puerto Rico, and the Virgin Islands ... and we have no desire to have them introduced in the United States other than under strict regulations. Dkt. 31-1 at 48 (emphasis added). This explanation supports the conclusion that the relevant language was added to the statute to prevent the spread of invasive species between Hawaii and overseas possessions and the continental United States. Not only did the Interior Department witness describe the immediate purpose of the provision in these narrow terms, but he explained that the prior version of the Lacey Act was broadened only “a bit.” That description is at odds with Defendants’ argument. Amending a law that previously reached only foreign imports to criminalize all interstate shipments of listed species would have gone far beyond an incremental broadening of the statute’s scope. The Department of the Interior’s testimony also describes the amendment in terms that avoid the textual ambiguity described above. According to the Department’s witness, the amendment “prohibit[s] the shipment between the Continental United States and Hawaii, Puerto Rico, and the Virgin Islands.” Id. (emphasis added). Although directed at the problem of the mongoose, this description of the law’s reach is unambiguous: It reaches shipments between “the Continental United States” and the offshore portions of the territorial United States. Other statements in the legislative history confirm that the language was not intended dramatically to expand the scope of conduct prohibited under the Lacey Act. Before the 1960 amendments, the Lacey Act barred “importation into the United States or, any Territory or district thereof’ of listed species, but did not address their domestic transportation. Dkt. 31-1 at 12-13. The Department of the Interi- or’s statement describing the draft legislation as “a bill to clarify certain provisions of the criminal code,” id. at 10 (emphasis added), suggests that the agency that drafted the legislation did not intend to ask that Congress criminalize a broad swath of previously legal activity. Importantly, the House and Senate committee reports on the legislation confirm that view. The House Report described the legislation as “clarifying certain provisions of the criminal code relating to the importation or shipment of injurious [animals],” and noted that the “amendments [were] technical in nature and designed to bring the legislation in accord with the general structure of title 18, United States Code.” Dkt. 31-1 at 7-8. The Senate Report used very similar language. Id. at 15-16 (“The purpose of the bill is to clarify and to make more inclusive, in the interest of good administration and enforcement, certain provisions of the Criminal Code.... ”). Even more striking is the absence in either the House or Senate Reports of any discussion of whether, or how, the law might apply to purely domestic shipments within the continental United States. When describing which agencies would implement the amendment, the Department of the Interior stated that the Secretary would “establish a permit system,” the Department “would need to check the facilities of applicants for such permits, and also issue the permits,” and “[i]t would fall to the U.S. Customs Service to effect inspection at the points of entry and reject or admit such items on the basis of existing regulations and appropriate related permits.” Id. at 43 (emphasis added). The Interior Department never described any plan or proposed delegation of authority to investigate interstate shipment of listed species. The Department’s testimony also indicates that it was aware that criminal statutes are interpreted narrowly and that it took care when drafting the legislation to speak unambiguously where it intended to expand the scope of prohibited conduct. When discussing amendments to former § 43, which prohibits transportation of species possessed or taken in violation of state or federal law, the Department noted that it “must be borne in mind that the statute is penal in nature and under a well-established rule of construction it must be construed strictly and all reasonable doubts in its interpretation resolved in favor of persons accused of violating its provisions.” Dkt. 81-1 at 45. It strains credulity to imagine that criminal legislation drafted and enacted with this principle in mind would adopt a sweeping expansion of the conduct it prohibited through the (at best) obscure language at issue here, without any mention by the Department of the Interior or the congressional committees of jurisdiction. The Court has been unable to identify any evidence — and Defendants have not pointed to any — that Congress or the Department of the Interior believed in 1960 that the Lacey Act amendments would prohibit all interstate transportation of listed species. The narrow reach of the 1960 amendments is confirmed, moreover, by the Department of the Interior’s consistent interpretation in the two decades following their enactment. Beginning in 1973, the Department issued a series of proposals that would have effectively reversed the species-designation procedure under the Lacey Act: Rather than enumerate a list of injurious species, the Interior Department proposed categorizing all species as injurious by default, exempting only those it determined to be “low risk.” See 38 Fed.Reg. 34970 (Dec. 20, 1973). In the course of this rulemaking effort, the Department repeatedly proposed rules that explicitly adopted the narrow reading of the Lacey Act’s prohibition on shipments of listed species. See 40 Fed.Reg. 7935, 7936 (Feb. 24,1975) (“Interstate shipments are not affected, except shipments between noncontinental parts of the United States (island ecosystems such as Hawaii and Puerto Rico) and the continental United States.”); 42 Fed.Reg. 12972, 12974 (Mar. 7, 1977) (“Pursuant to the statute, the proposed regulations would also prohibit the shipment of injurious wildlife between any two of the following geographic areas: the continental United States, the State of Hawaii, Puerto Rico, or any possession of the United States.”). A Department representative confirmed this view in a 1974 hearing before the House Subcommittee on Fisheries and Wildlife Conservation and the Environment. When asked how the proposed rule would address “the problem of exotic species that are already in this country,” a witness from the Fish and Wildlife Service testified that “there [was] no restriction ... in section 42 of the Lacey Act to interstate shipments, with the possible exception of restrictions from areas off the continental United States, such as Puerto Rico, the Virgin Islands, and Hawaii.” Dkt. 28-3 at 3. Thus, “the breeder of pheasants, or black buck, or what have you, in the United States [would] not have any restrictions on the movement or possession of the animals that are already present in the United States. The restrictions ... apply to importations.” Id. The Department of the Interior did not ultimately adopt its injurious-by-default approach in a final rule, but its statements in proposed rules and in testimony before Congress made clear that the Department did not understand the Lacey.Act to prohibit interstate shipments of injurious species, with the “possible exception” of shipments between outlying territories and the continental United States. This evidence reflects the view of the agency that drafted the 1960 Lacey Act amendments and confirms the clear import of the amendments’ legislative history. It also vindicates the better reading of the admittedly unclear language of the Lacey Act itself. In light of these considerations and applying the “traditional tools of statutory construction,” the Court concludes that Plaintiffs’ interpretation reflects the unambiguous intent of Congress. Thus, even were Chevron to apply, Plaintiffs would prevail at step one of the analysis because Congress did not leave a gap for the agency to fill, c. Subsequent Legislative History Defendants base their contrary view of the legislative history on developments that took place decades after the language at issue was enacted. At some point in the 1980s, the Interior Department abandoned the interpretation of the relevant language that it had previously presented to Congress and applied for approximately two decades. As noted above, in 1989 the Department began inserting language in rules listing species as injurious that purported to prohibit all interstate transportation of the listed species. See 54 Fed.Reg. 22286, 22287 (May 23, 1989) (“interstate transportation [of mitten crabs] ... for any purpose not otherwise permitted, would be prohibited.”). This view has been reflected in the legislative history of subsequent amendments to the Lacey Act. In one case, Congress passed a law exempting a water district’s pipeline from the Lacey Act because the pipeline would transport a listed species across state lines. In two other cases, Congress has passed laws explicitly listing species under the Act based, in part, on at least some members’ understanding that the Act would prohibit interstate transportation of the newly listed species. i. The 1990 zebra mussel legislation The Department’s new view was promptly reflected in the legislative history of an amendment to the Lacey Act. In 1990, Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act, Pub.L. 101-646, which, among other provisions aimed at limiting the spread of the zebra mussel in the United States, amended 18 U.S.C. § 42 to list the zebra mussel as an injurious species. Congress was alarmed that the zebra mussel had, in the two years since it was first discovered in the United States, “spread over a 10,000 square mile area, infesting the Lake Erie shoreline from Detroit to Buffalo.” Dkt. 44-1 at 11 (1990) (statement of Sen. Specter). Zebra mussels are unimposing mollusks about “the size of a quarter.” Id. They can affix themselves to almost any surface, however, and form massive agglomerations large enough to block water intake pipes. Id. They also reproduce prolifically and compete with local fish populations for nutrients — so successfully that members of Congress predicted that economic damage attributable to the zebra mussel could reach as much as $5 billion in the 1990s. Id. (“Projections of the economic damage caused by the zebra mussel are $500 million each year in Lake Erie alone and $3 to $4 billion for all areas impacted by the mussels in the next 10 years.”); see also id. at 11-12 (“Some estimate that the combined costs of the damage to infrastructure and fishery of the Lakes could climb to $5 billion over the next 10 years.”) (statement of Sen. Glenn); Pub.L. 101-646 § 1002(a) (“the potential economic disruption ... has been estimated at $5,000,000,000 by the year 2000, and the potential disruption to the diversity and abundance of native fish and other species could be severe”). Congress also evinced concerns about the spread of the zebra mussel outside the Great Lakes. Senator Glenn warned that it was “only a matter of time before the zebra mussel infestation spreads to two-thirds of the Nation’s freshwater system unless we work to control it.” Id. at 12; see also id. at 11 (“Experts anticipate that within 10 years this creature is likely to be found in two-thirds of the United States”) (statement of Sen. Specter); Pub.L. 101— 646 § 1002(a) (“the zebra mussel ... if left uncontrolled, is expected to infest over two-thirds of the continental United States through the unintentional transportation of larvae and adults by vessels operating in inland waters”). Senator Glenn explained, “[t]he bill also addresse[d] other probable pathways of zebra mussel spread. In particular, it amende[d] the Lacey Act to prevent the interstate transportation of the zebra mussel in commerce.” Dkt. 44-1 at 12 (emphasis added). The Senate committee report on the zebra mussel legislation noted Congress’s finding that the zebra mussel “currently ' infest[ed] the lower Great Lakes basin with the potential to spread to areas outside the basin.” S. Rep. 101-523 (1990). Significantly, the report also stated that the provision amending the Lacey Act “would lead to the prohibition of the interstate transport of zebra mussels for commercial purposes.” Id. (emphasis added). There is, however, at least one statement in the legislative history of the bill evincing the Department’s original understanding of the Lacey Act’s scope. In written testimony on a similar bill introduced in the House of Representatives, the Assistant Secretary for Fish and Wildlife and Parks stated that “designation of zebra mussels as injurious wildlife” would “have no [ejffect on the interstate transport of zebra mussels.” Dkt. 50-1 at 32. She made an identical statement in written testimony before a Senate subcommittee. Dkt. 50-2. This is inconsistent with the Interior Department’s almost-concurrent statements in promulgated rules indicating that the effect of a listing under the Lacey Act would be to ban interstate transportation of the listed species. See 54 Fed.Reg. 22286, 22287 (May 23, 1989); 55 Fed.Reg. 17439, 17440 (Apr. 25, 1990). It injects at least some uncertainty into the 1990 legislative record. ii. The 2010 bighead carp legislation Twenty years after Congress amended the Lacey Act to list the zebra mussel as an injurious species, it enacted the Asian Carp Prevention and Control Act to target another invasive species. See Pub.L. Ill— 307 (2010). Once again, the legislative history of its amendment suggested that Congress understood the Lacey Act to prohibit all interstate transportation of listed species. Bighead carp — a species of Asian carp — can grow to five feet in length and more than 100 pounds, and they eat up to 20 percent of their body weight per day in plankton, depriving native aquatic species of needed nutrients. See, e.g., Margaret E. Vroman, The Asian Carp: An Imminent Threat to the Great Lakes?, 90 Mich. Bar J. 25, 26 (2011). The species was introduced into the United States from China in the 1970s “to eat the algae clotting fish farms in the South,” but “a series of floods over the years helped them to escape their controlled environment.” Dan Barry, On an Infested River, Battling Invaders Eye to Eye, The New York Times, September 15, 2008 at A13 (“Cue the ‘Jaws’ theme.”). The species received wary attention as it spread north up the Mississippi river in the decades following its introduction, but concern intensified dramatically after researchers discovered bighead carp DNA “in the Great Lakes vicinity” and past an electric dispersal barrier intended to repel the fish. S. Rep. 111-181 (2010). These events spawned considerable congressional concern. Representatives noted that “these enormous fish have become a menace to native species and their habitats,” Dkt. 44-5 at 2 (remarks of Rep. Poe), and worried that the bighead carp would “threaten not only the commercial but recreational fishing” throughout the Great Lakes, id. (statement of Rep. Co-nyers); see also id. at 3 (“Asian carp are the single greatest biological threat to [the Great Lakes ecosystem].”) (statement of Rep. Biggert). Importantly, Congress appears not to have acted under, the impression that it could eradicate the bighead carp from the Mississippi — instead, members focused on the need to “do everything possible to prevent these invasive fish from harming other areas of the United States.” Id. (statement of Rep. Pitri). Congress’s solution to the problem was a single-purpose law designating the bighead carp as an injurious species under the Lacey Act. The legislative history contains a substantial number of statements suggesting that Congress understood the listing would prohibit interstate transportation of bighead caigx The Senate Report states that the legislation would “add the bighead carp ... to the list of injurious species that are prohibited from being traded in interstate commerce or imported into the United States.” S. Rep. 111-181 (2010). Representative Conyers described the bill as “prohibit[ing] importation and interstate shipment of certain species of carp and ... addfing] the bighead variety of the species commonly known as Asian carp to the list of injurious species that are prohibited from being shipped in or imported into the United States.” Dkt. 44-5 at 2. Several other members of Congress made similar statements. See id. (“This designation prohibits the importation and interstate shipment of Asian carp.”) (statement of Rep. Poe); id. at 3 (“For many years ... a number of us from the Great Lakes region have been urging the Fish and Wildlife Service to include bighead carp on the list of injurious species under the Lacey Act and so minimize the risk of further harm by prohibiting the importation and interstate transportation of live Asian carp without a permit.”) (statement of Rep. Levin); 155 Cong. Rec. 7319 (2009) (“Listing the Bighead carp as injurious would minimize the risk of intentional introduction by prohibiting the importation and interstate transportation of live Asian carp without a permit”) (statement of Sen. Levin). Plaintiffs note that other representatives who spoke on the bill did not indicate whether they believed that a listing under the Lacey Act barred interstate transportation of the listed species. See Dkt. 44-5 at 3 (Dec. 1, 2010) (“This legislation takes an important step in restricting the transportation of the Big Head Asian Carp by listing it as an injurious species under the Lacey Act, prohibiting this fish from being shipped or imported into the United States.”) (Statement of Rep. Kaptur); id. (bill would add bighead carp to the “list of injurious species under the Lacey Act and prevent their sale or importation into the United States”) (statement of Rep. Big-gert). Although Plaintiffs are correct that both mentioned importation without discussing interstate shipments, both Representative Biggert and Representative Kap-tur previously signed a letter to the Fish and Wildlife Service (“FWS”) stating that “[l]isting these fish would ... prohibit interstate transportation.” Dkt. 44-3. Plaintiffs have not identified any statement in the legislative history of the bighead carp bill that disputes or contradicts the Senate report’s characterization of the law. Hi. The 2012 Lake Texoma legislation A third, more recent legislative development also suggests that recent Congresses have understood the Lacey Act to reach interstate transportation. In 2012, Congress passed a law that exempted certain water transfers between Oklahoma and Texas from the Lacey Act. See Lake Pontchartrain Basin Restoration Program, § 5, Pub.L. 112-237 (Dec. 28, 2012). In 1989, the North Texas Municipal Water District (the “Water District”) obtained approval to construct a pumping station that would transport water from Lake Texoma, a reservoir on the Red River, to supply a reservoir in the Trinity River system. See H.R. Rep. 112-657 (2012). Unlike the Red River, which forms much of the border between Oklahoma and Texas and flows east into the Mississippi, the Trinity River flows south through eastern Texas into the Gulf of Mexico. In 2000, a realignment of the Texas-Oklahoma border left a portion of the Lake Texoma water intake facility in Oklahoma. Id. Thus, when zebra mussels were discovered in Lake Texoma in 2009, the FWS advised the Water District that transfer of water out of Lake Texoma via the intake facility would constitute a “violation of the Lacey Act because invasive zebra mussels would be transported across state lines” and into the uninfested Trinity River basin. Id. The Water District eventually determined that it would construct a closed pipeline connecting the pumping station on Lake Texoma to a water treatment facility in Texas, “where the zebra mussels w[ould] be completely destroyed.” Id. The FWS, however, “indicated [it] laek[ed] the statutory authority to tell the Water District that this pipeline w[ould] comply with the Lacey Act.” Id. The proposed legislation “solve[d]” this “problem ... by recognizing that the Lacey Act does not apply to the Lake Texoma water transfers.” Id. In a separate statement, Representative Mar-key also noted that zebra mussels were “a species designated by the Fish and Wildlife Service as ‘injurious’ and therefore illegal to transport across state lines,” and emphasized that, although he supported the proposed legislation, he believed it “should not set a precedent for making exemptions to the Lacey Act.” Id. This legislation, at a minimum, further evidences recent congressional awareness of the Interior Department’s interpretation of the Lacey Act. d. Effect of the Subsequent History The parties disagree about the significance of these post-enactment congressional actions. According to Plaintiffs, the Department of the Interior’s interpretations of the Lacey Act in the 1970s confirm what Plaintiffs view to be the better reading of the statutory language-that the Act does not bar interstate transportation of listed species within the continental United States. The developments after 1980, in their view, have no interpretative significance. Dkt. 45 at 6. Plaintiffs contend that these events reflect isolated congressional responses to “discrete exigencies,” rather than any intent to re-evaluate the scope of the Lacey Act for all purposes. Id. Plaintiffs emphasize that the zebra mussel and bighead carp bills received comparatively little ■ attention when they were enacted, id. at 8, and argue that, in any event, neither is sufficient to establish that Congress ratified the Interior Department’s more recent interpretations of the statute. Although they acknowledge that “reenactment” of a statute “without change after a course of administrative interpretation is tantamount to legislative ratification of the interpretation,” Thompson v. Clifford, 408 F.2d 154, 164 (D.C.Cir.1968), they argue that the Lacey Act has never been “reenacted” or so significantly amended to establish ratification, see Dkt. 45 at 10-11 (citing Pub. Citizen, Inc. v. Dep’t of Health & Human Servs., 332 F.3d 654, 668 (D.C.Cir.2003), and Alexander v. Sandoval, 532 U.S. 275, 292, 121 S.Ct. 1511, 149 L.Ed.2d 517 (2001)). They also dispute that Congress was, as a whole, sufficiently aware of Department’s more recent interpretations of the Lacey Act to support an inference of ratification. See Dkt. 45 at 11. Defendants, unsurprisingly, view the significance of these developments differently. They note that the Department of the Interior’s statements in proposed rules and before Congress in the 1970s were made in the course of an abortive regulatory effort that would have greatly expanded the number of species listed under the Lacey Act. Although a more circumspect view of the interstate transportation bar may have made sense in the context of that proposed scheme, they assert that the Department was free to assume its current position when it abandoned that effort. See Chevron, 467 U.S. at 863, 104 S.Ct. 2778 (when an agency changes its interpretation of a statute, the new interpretation is still entitled to deference so long as it is reasonable). Defendants also stress that Congress actually amended the Lacey Act to list additional species after the committee reports they cite, and that the amendments involved species that were already present in the continental United States. Indeed, in Defendants’ view, the zebra mussel and bighead carp amendments bear more weight than normal “post-enactment legislative history” because they amended the precise statute at issue and, by refraining from changing the language of the interstate shipment provision, declared “the intent of [the] earlier statute.” Red Lion Broadcasting Co. v. FCC, 395 U.S. 367, 380-81, 89 S.Ct. 1794, 23 L.Ed.2d 371 (1969) (“Subsequent legislation declaring the intent of an earlier statute is entitled to great weight in statutory construction”). According to Defendants, those two amendments show that Congress understood the Lacey Act to bar all interstate transportation of listed species and that Congress “ratified” that permissible interpretation of the law. Dkt. 48 at 5. In general, “ ‘the views of a subsequent Congress form a hazardous basis for inferring the intent of an earlier one.’ ” Public Citizen Health Research Grp. v. FDA 704 F.2d 1280, 1289 n. 26 (D.C.Cir.1983) (quoting Consumer Prod. Safety Comm’n v. GTE Sylvania Inc., 447 U.S. 102, 117, 100 S.Ct. 2051, 64 L.Ed.2d 766 (1980); see also O’Gilvie v. United States, 519 U.S. 79, 90, 117 S.Ct. 452, 136 L.Ed.2d 454 (1996) (“[T]he view of a later Congress cannot control the interpretation of an earlier enacted statute.”). The actions of a subsequent Congress can, however, inform the meaning of an earlier enacted statute under two narrow circumstances: Congress may ratify an administrative interpretation of a law when it reenacts or substantially amends the earlier enactment, and Congress may repeal or amend a law by implication. Neither approach to interpretation is favored under the law, and both 'are subject to significant limitations. i. Ratification Defendants frame their argument in terms of congressional ratification of the Department of the Interior’s broad interpretation of the Lacey Act. Under the ratification canon, “Congress is presumed to be aware of an administrative or judicial interpretation of a statute and to adopt that interpretation when it re-enacts a statute without change.” Public Citizen v. FAA 988 F.2d 186, 194 (D.C.Cir.1993) (citation and quotation marks omitted). Three considerations, however, weigh — to varying degrees — against application of that canon here. First, the ratification canon is of “little assistance” where Congress has not re-enacted the entire statute at issue or significantly amended the relevant provision. See Public Citizen, Inc. v. Dep’t of Health and Human Servs., 332 F.3d at 668. As the'Supreme Court has explained, “when ... Congress has not comprehensively revised a statutory scheme but has made only isolated amendments,” a court cannot “assert with any degree of assur-anee that congressional failure to act represents affirmative congressional approval of the [administrative] statutory interpretation.” Alexander v. Sandoval, 532 U.S. at 292, 121 S.Ct. 1511 (citations and internal quotations omitted). Here, Congress did not re-enact the entire Lacey Act and did not amend the relevant language in any of the three subsequent enactments upon which Defendants rely. Defendants point to Kay v. FCC, 443 F.2d 638, 646-47 (D.C.Cir.1970), where the Court of Appeals concluded Congress had ratified an interpretation of one statutory provision by amending a related provision. In that case, however, the Court of Appeals had already concluded that the administrative interpretation was, in any event, the better reading of the statute, and the Court merely concluded that related legislative amendments made after Congress “fully reviewed” the agency’s rulings provided some additional “persuasive weight.” Id. at 646. Second, the Supreme Court has cautioned that courts should be “extremely hesitant to presume general congressional awareness of the [agency’s] construction based only upon a few isolated statements in the thousands of pages of legislative documents.” SEC v. Sloan, 436 U.S. 103, 121, 98 S.Ct. 1702, 56 L.Ed.2d 148 (1978). As the Court explained in TVA v. Hill, 437 U.S. 153, 98 S.Ct. 2279, 57 L.Ed.2d 117 (1978), its hesitation to presume congressional awareness in Sloan came against the backdrop of “a 34-year-old practice of the Securities and Exchange Commission,” and “despite the fact that the Senate Committee having jurisdiction over the Commission’s activities had long expressed approval of the practice.” Id. at 192, 98 S.Ct. 2279 (emphasis omitted); see also Sloan, 436 U.S. at 121, 98 S.Ct. 1702 (“[L]anguage in a Committee Report, without additional indication of more widespread congressional awareness, is simply not sufficient to invoke the presumption in a case such as this.”). Here, although it is clear that many members of Congress were aware of the Interior Department’s broad construction of the Lacey Act at the time Congress enacted each of the three subsequent statutes — and, indeed, that construction is referenced in committee reports, see S. Rep. 101-523 (1990); S. Rep. 111-181 (2010); H.R. Rep. 112-657 (2012) — the legislative record is not uniform, see Dkt. 50-1 at 32, and, more importantly, the Supreme Court has suggested that even this type of broad awareness of an administrative practice may not be enough for purposes of the ratification canon. The Court need not, however, decide this issue in light of the remaining hurdles Defendants face. The third difficulty with De-fendánts’ efforts to invoke the ratification doctrine is the clearest, and it is disposi-tive. The Supreme Court has repeatedly recognized that “re-enactment cannot save a regulation which contradicts the requirements of the statute itself.” Leary v. United States, 395 U.S. 6, 24, 89 S.Ct. 1532, 23 L.Ed.2d 57 (1969) (quotation marks and alterations omitted); see also Demarest v. Manspeaker, 498 U.S. 184, 190, 111 S.Ct. 599, 112 L.Ed.2d 608 (1991) (“Where the law is plain, subsequent reenactment does not constitute an adoption of a previous administrative construction.”). These cases rely on the basic principle that Congress cannot “ ‘add to or expand’ ” the scope of a statute whose meaning is plain without affirmatively amending the law. Leary, 395 U.S. at 25, 89 S.Ct. 1532 (quoting Comm’r of Internal Revenue v. Acker, 361 U.S. 87, 93, 80 S.Ct. 144, 4 L.Ed.2d 127 (1959)). Following Sloan, 436 U.S. at 122, 98 S.Ct. 1702, which questioned, in dicta, whether a subsequent re-enactment coüld trump “the rather plain meaning of’ the statutory language at issue, the Court bf Appeals has observed “that Congress cannot by its silence ratify an administrative interpretation that is contrary to the plain meaning of the Act.” Ashton v. Pierce, 716 F.2d 56, 63 (D.C.Cir.1983). The principle applies, moreover, even where the competing construction of the Act is “perhaps not an impossible” one, Sloan, 436 U.S. at 112, 98 S.Ct. 1702, and where a court arrives at the “plain meaning