Full opinion text
HOLMES, Circuit Judge. In this consolidated appeal, Victor Wayne Hooks, an Oklahoma state prisoner facing the death penalty, appeals two orders of the district court denying him habeas relief. He seeks relief on three alternative grounds: (1) he is mentally retarded and thus categorically ineligible for the death penalty; (2) aspects of his mental-retardation trial (“Atkins trial”) denied him his Fifth and Sixth Amendment rights to due process and a fair trial; and (3) his counsel was ineffective during both the guilt and sentencing phases of his original trial. Grounds 1 and 2 arise in Appeal No. 10-6076; ground 3 arises in Appeal No. 03-6049. The district court granted certificates of appealability on all claims. Our disposition, in brief, is as follows: (1) in No. 10-6076, we AFFIRM the judgment of the district court denying habeas relief on all claims arising out of Mr. Hooks’s Atkins trial; and (2) in No. 03-6049, we (a) AFFIRM the judgment of the district court denying habeas relief as to Mr. Hooks’s 1989 conviction, but (b) REVERSE the judgment of the district court and conditionally grant the writ of habeas corpus as to his sentence. I. Factual and Procedural Background A. At the time of her death, Shalimein Blaine was the common-law wife of Victor Hooks. The couple had lived together for four years. They were the parents of a one-year-old daughter, and Ms. Blaine was twenty-four-weeks pregnant with their second child. On the evening of October 6, 1988, Mr. Hooks left his wife’s apartment and went to the home of her mother, Virginia Plumley, less than a block away. He told Ms. Plumley that Ms. Blaine had been beaten and raped and needed to be taken to the hospital. He then left. Ms. Plumley and her daughter, Amanda, followed Mr. Hooks back to the apartment, and when they arrived, they watched him load an unconscious Ms. Blaine into the car. She was unclothed and wrapped in nothing but a blanket. Ms. Plumley noticed that Ms. Blaine’s arms and legs were covered in bruises, her face was swollen, and her head had been partially shaved. As they drove to the hospital, Ms. Plumley asked Mr. Hooks what happened. He said Ms. Blaine had gone for a walk and returned two hours later, beaten and bloodied. When Ms. Plumley asked why he had shaved Ms. Blaine’s head, Mr. Hooks responded that he had not done that and that it must have been done by the person who beat and raped her. When Ms. Blaine arrived at St. Anthony Hospital in Oklahoma City, she was clinically dead. An ultrasound revealed that her unborn child was also dead, with a ruptured liver and bruising on its abdomen and head due to blunt-force trauma. Although doctors were initially able to reestablish Ms. Blaine’s heartbeat and pulse, she was pronounced officially dead the following morning. After preliminary questioning by Oklahoma City police officers, Mr. Hooks agreed to let the officers search Ms. Blaine’s apartment. There, they discovered blood on the bed, on the carpet near the bed, and on several wash cloths and towels in a clothes hamper. They also found some hair in a trash can in the apartment. A search of a nearby dumpster revealed more bloody wash cloths, bloody clothing, and a large clump of hair. Police brought Mr. Hooks to the Oklahoma City police station, where he was questioned by Detectives Eric Mullenix and Randy Scott. Mr. Hooks initially told detectives that Ms. Blaine had left the apartment for a walk, returned home, knocked on the door, and fell into his arms when he answered. He claimed she had been beaten and raped. According to Mr. Hooks, he then left the apartment to notify Ms. Plumley, and when he returned, Ms. Blaine was in the bathtub. He wrapped her in a blanket and took her to the hospital. When detectives confronted Mr. Hooks with the bloody items and hair they had found, he began to cry and said he wanted to tell the truth. He told detectives that he and Ms. Blaine had been fighting: Ms. Blaine slapped him, and he then struck her, knocked her to the ground, and began kicking her in the stomach and face. He subsequently removed her clothing, placed her in the bathtub, and shaved a portion of her head. He did this, he claimed, because he was looking for head injuries. He then cleaned up the apartment. He also removed the blood from his one-year-old daughter, who had gotten it on her in the course of her mother’s beating. He placed the bloody clothing and clump of hair in the nearby dumpster. B. Mr. Hooks was charged by information in October 1988 with murder in the first degree of Shalimein Blaine and with manslaughter in the first degree for the death of the unborn quick child. At his trial in the District Court of Oklahoma County, Oklahoma, he was represented by Ronald Evans, a private attorney retained by Mr. Hooks’s mother, Clara Hooks. Mr. Evans, after consulting with experts, decided not to pursue an insanity defense, believing there was an insufficient factual basis for it. Instead, and in light of Mr. Hooks’s confession, he focused on obtaining a conviction for the lesser-included offense of second-degree murder or first-degree manslaughter with respect to Ms. Blaine. He sought to show that Mr. Hooks had acted in the heat of passion or with a depraved mind, not with malice aforethought. The trial court, however, refused to instruct the jury on the lesser-included offenses. On May 10, 1989, the jury found Mr. Hooks guilty of first-degree murder with respect to Ms. Blaine and first-degree manslaughter with respect to the unborn quick child. After a relatively brief sentencing phase, the jury sentenced Mr. Hooks to death for the crime of first-degree murder and to five hundred years’ imprisonment for the crime of first-degree manslaughter. The court entered judgment and sentenced Mr. Hooks accordingly- Post-trial proceedings followed a long and serpentine path through the state and federal judicial systems, which we briefly review below. To summarize, we have consolidated two separate appeals for our review. The first, No. 03-6049, concerns claims of ineffective assistance of trial counsel pertaining to both the guilt and sentencing phases of Mr. Hooks’s original trial. The second, No. 10-6076, involves several claims arising out of a subsequent trial in Oklahoma district court on whether Mr. Hooks is mentally retarded. 1. Mr. Hooks’s conviction and sentence were affirmed on direct appeal by the Oklahoma Court of Criminal Appeals (“OCCA”). See Hooks v. State, 862 P.2d 1273, 1284 (Okla.Crim.App.1993), cert. denied, 511 U.S. 1100, 114 S.Ct. 1870, 128 L.Ed.2d 490 (1994). As relevant here, Mr. Hooks claimed on direct appeal that his trial counsel was ineffective for advising him not to testify at trial — a claim that the OCCA rejected on the merits. Id. at 1283. Mr. Hooks then sought postconviction relief, arguing that his trial counsel was ineffective for a host of other reasons. The OCCA found these claims procedurally barred because they were not raised on direct appeal, and it denied postconviction relief. See Hooks v. State, 902 P.2d 1120, 1122 n. 4 (Okla.Crim.App.1995), cert. denied, 517 U.S. 1145, 116 S.Ct. 1440, 134 L.Ed.2d 561 (1996). In December 1996, Mr. Hooks filed an application for writ of habeas corpus in the United States District Court for the Western District of Oklahoma, asserting numerous claims. His claims of ineffective assistance of trial counsel encompassed the claims he had raised before the OCCA on both direct appeal and postconviction review. The district court held an evidentiary hearing in April 1997. It subsequently denied habeas relief but granted a certificate of appealability (“COA”) on the ineffective-assistance claims. See Hooks v. Ward, No. CIV-96-732-M (W.D.Okla. Mar. 30, 1998) [hereinafter Hooks Habeas I]. On appeal to a panel of this court, the claims received bifurcated treatment. See Hooks v. Ward, 184 F.3d 1206, 1213-20 (10th Cir.1999). With respect to the claim that trial counsel was ineffective for advising Mr. Hooks not to testify, our review was constrained by the deferential standards of the Antiterrorism and Effective Death Penalty Act (“AEDPA”). See 28 U.S.C. § 2254(d). We held that the OCCA did not unreasonably apply Strickland v. Washington, 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), when it denied the claim on the merits. 184 F.3d at 1220. As for the other allegations of ineffective assistance, to which the OCCA applied a procedural bar on postconviction review, we remanded for a determination of whether the procedural bar was adequate to preclude federal habeas review of the merits. See id. at 1217-18. On remand, the district court held that the procedural bar was inadequate and reaffirmed its previous ruling denying habeas relief on the merits. Hooks v. Ward, No. CIV-96-732M (W.D.Okla. Jan. 27, 2003). Mr. Hooks filed a timely notice of appeal, and the district court granted a COA. The appeal was docketed at No. 03-6049. 2. In the meantime, the Supreme Court decided Atkins v. Virginia, 536 U.S. 304, 321, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002), in which it held that the execution of a mentally retarded person is “cruel and unusual punishment[ ]” prohibited by the Eighth Amendment. In December 2002, Mr. Hooks filed a second application for postconviction relief with the OCCA, alleging that his execution would violate the Eighth Amendment, pursuant to Atkins. We subsequently abated Appeal No. 03-6049 to allow Mr. Hooks to litigate the Atkins claim in state court. The OCCA remanded the matter to the Oklahoma County District Court for a jury trial on whether Mr. Hooks is mentally retarded. In June 2004, after a six-day trial, a jury concluded that Mr. Hooks is not mentally retarded, and the OCCA upheld that determination on appeal. See Hooks v. State, 126 P.3d 636, 645 (Okla.Crim.App.2005) [hereinafter Hooks Atkins Appeal ], cert. denied, 547 U.S. 1078, 126 S.Ct. 1790, 164 L.Ed.2d 531 (2006). Mr. Hooks then sought collateral relief on claims arising out of his Atkins trial, which the OCCA denied in an unpublished decision. See Hooks v. State, No. PCD-2006-350 (Okla.Crim.App. Oct. 10, 2006) [hereinafter Hooks Atkins Collateral ]. We authorized Mr. Hooks to file a second or successive habeas petition to address his Atkins claims. See Order at 2, Hooks v. Sirmons, Nos. 03-6049, 06-6105 (10th Cir. Mar. 31, 2006). Mr. Hooks filed his second petition in April 2006, challenging the procedures and result of the Atkins trial. The district court entered a stay pending the OCCA’s collateral review of the claims. After the OCCA denied relief, Mr. Hooks filed an amended federal habeas petition in December 2006. The district court denied habeas relief on the Atkins claims. See Hooks v. Workman, 693 F.Supp.2d 1280, 1325 (W.D.Okla.2010) [hereinafter Hooks Habeas II ]. Mr. Hooks filed a notice of appeal, the district court granted a COA, and the appeal was docketed at No. 10-6076. Appeal No. 03-6049 (the ineffective-assistance claims) and Appeal No. 10-6076 (the Atkins claims) have been consolidated for our review. II. Discussion Mr. Hooks seeks habeas relief on three alternative grounds. With respect to his Atkins trial (Appeal No. 10-6076), he asserts (1) that he is mentally retarded and his execution would violate Atkins, and (2) that numerous procedural irregularities made his Atkins trial fundamentally unfair. With respect to his original trial (Appeal No. 03-6049), he asserts (3) that his counsel was ineffective during both the guilt and sentencing phases. As to grounds one and two, we agree with the district court that in light of AEDPA’s deferential standard, Mr. Hooks is not entitled to habeas relief. (See Parts II.B. and II.C. below.) As to ground three, our review is not constrained by AEDPA. We agree with the district court that counsel was not ineffective during the guilt phase of Mr. Hooks’s original trial. {See Part II.D.l. below.) However, we part ways with the district court regarding counsel’s performance during the sentencing phase. With respect to that aspect of the claim, we reverse the district court’s judgment and conditionally grant the writ. (See Part II.D.2. below.) A. Standard of Review AEDPA circumscribes our review of federal habeas claims that were adjudicated on the merits in state-court proceedings. See, e.g., Byrd v. Workman, 645 F.3d 1159, 1165 (10th Cir.2011). An applicant is not entitled to relief unless he can demonstrate that the state court’s resolution of his claims was “contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States” or “was based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.” 28 U.S.C. § 2254(d)(1), (2); accord Phillips v. Workman, 604 F.3d 1202, 1209 (10th Cir.2010). This “ ‘highly deferential standard for evaluating state-court rulings[ ]’ ... demands that state-court decisions be given the benefit of the doubt.” Woodford v. Visciotti 537 U.S. 19, 24, 123 S.Ct. 357, 154 L.Ed.2d 279 (2002) (per curiam) (quoting Lindh v. Murphy, 521 U.S. 320, 333 n. 7, 117 S.Ct. 2059, 138 L.Ed.2d 481 (1997)). Under § 2254(d)(1), the threshold question is whether there exists clearly established federal law, an inquiry that focuses exclusively on holdings of the Supreme Court. House v. Hatch, 527 F.3d 1010, 1015 (10th Cir.2008) (calling Supreme Court holdings “the exclusive touchstone for clearly established federal law”). “The absence of clearly established federal law is dispositive under § 2254(d)(1).” Id. at 1018 (citing and discussing Carey v. Musladin, 549 U.S. 70, 127 S.Ct. 649, 166 L.Ed.2d 482 (2006)). If clearly established federal law exists, a state-court decision is “contrary to” it “if the state court applies a rule different from the governing law set forth in [Supreme Court] cases, or if it decides a case differently than [the Supreme Court has] done on a set of materially indistinguishable facts.” Bell v. Cone, 535 U.S. 685, 694, 122 S.Ct. 1843, 152 L.Ed.2d 914 (2002). A state-court decision is an “unreasonable application” of clearly established federal law when the state court “identifies the correct governing legal principle from th[e Supreme] Court’s decisions but unreasonably applies that principle to the facts of petitioner’s case.” Wiggins v. Smith, 539 U.S. 510, 520, 123 S.Ct. 2527, 156 L.Ed.2d 471 (2003) (quoting Williams v. Taylor, 529 U.S. 362, 413, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000)) (internal quotation marks omitted). “[R]eview under § 2254(d)(1) is limited to the record that was before the state court that adjudicated the claim on the merits.” Cullen v. Pinholster, — U.S. -, 131 S.Ct. 1388, 1398, 179 L.Ed.2d 557 (2011). Habeas relief is also warranted if the state court’s adjudication of a claim on the merits “resulted in a decision that was based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.” 28 U.S.C. § 2254(d)(2). As the plain terms of the statute indicate, we also must not stray from the record before the state court in conducting this AEDPA inquiry. Furthermore, factual findings of the state court are presumed correct unless the applicant rebuts that presumption by “clear and convincing evidence.” 28 U.S.C. § 2254(e)(1); accord Welch v. Workman, 639 F.3d 980, 991 (10th Cir.2011). “We review the district court’s legal analysis of the state court decision de novo.” Welch, 639 F.3d at 991 (quoting Bland v. Sirmons, 459 F.3d 999, 1009 (10th Cir.2006)) (internal quotation marks omitted). For federal habeas claims not adjudicated on the merits in state-court proceedings, we exercise our “independent judgment” and “review the federal district court’s conclusions of law de novo.” McCracken v. Gibson, 268 F.3d 970, 975 (10th Cir.2001). The district court’s factual determinations are reviewed for clear error. Id. Any state-court findings of fact that bear upon the claim are entitled to a presumption of correctness rebuttable only by “clear and convincing evidence.” 28 U.S.C. § 2254(e)(1); see Hooks v. Ward, 184 F.3d at 1223 (applying § 2254(e)(1)’s presumption of correctness to state-court factual findings bearing upon the claim, even though the claim was not adjudicated on the merits by the state court). B. Existence of Mental Retardation Mr. Hooks first asks us to find that he is mentally retarded and that his execution is categorically prohibited by the Eighth Amendment. An Oklahoma jury (hereinafter the “Atkins jury”) found that Mr. Hooks is not mentally retarded, and that determination was upheld by the OCCA on both direct appeal and collateral review. The essence of Mr. Hooks’s claim is a challenge to the sufficiency of the evidence. He argues: The [Atkins ] jury’s conclusion was based on insufficient evidence and [Mr. Hooks] separately asserts the trial evidence, coupled with the additional evidence appropriately presented in habeas, demonstrates he is so impaired [that] he falls within the range of mentally retarded offenders for which there is a national consensus against his execution. Aplt. Opening Br. at 20-21. The OCCA rejected this legal challenge, concluding that “a rational trier of fact could have found” that Mr. Hooks failed to show, by a preponderance of the evidence, that he is mentally retarded. Hooks Atkins Appeal, 126 P.3d at 641. As we will explain, the OCCA’s conclusion did not contravene clearly established federal law. We first set forth Oklahoma’s standard for finding a person mentally retarded within the meaning of Atkins. We then explain our standard of review in the habeas context for the unique sort of sufficiency challenge that Mr. Hooks presents here. Finally, we analyze whether the OCCA contravened clearly established federal law in its decision to uphold the Atkins jury’s finding, and we conclude that it did not. 1. In Atkins, the Supreme Court held that in light of a national consensus and its own precedents, execution of mentally retarded criminal defendants violates the Eighth Amendment’s prohibition on “cruel and unusual punishments.” See 536 U.S. at 311, 316-21, 122 S.Ct. 2242 (quoting U.S. Const, amend. VIII) (internal quotation marks omitted). The Court did not set forth a definition of mental retardation. Although it twice discussed clinical definitions of the term, see id. at 308 n. 3, 318, 122 S.Ct. 2242, it acknowledged that “[n]ot all people who claim to be mentally retarded will be so impaired as to fall within the range of mentally retarded offenders about whom there is a national consensus,” id. at 317, 122 S.Ct. 2242. The Court therefore left “to the States the task of developing appropriate ways to enforce the constitutional restriction upon their execution of sentences.” Id. (alterations omitted) (quoting Ford v. Wainwright, 477 U.S. 399, 416-17, 106 S.Ct. 2595, 91 L.Ed.2d 335 (1986)) (internal quotation marks omitted). In response to Atkins, the OCCA in Murphy v. State promulgated the following definition of mental retardation for use in capital trials: A person is “mentally retarded”: (1) If he or she functions at a significantly sub-average intellectual level that substantially limits his or her ability to understand and process information, to communicate, to learn from experience or mistakes, to engage in logical reasoning, to control impulses, and to understand the reactions of others; (2) The mental retardation manifested itself before the age of eighteen (18); and (3) The mental retardation is accompanied by significant limitations in adaptive functioning in at least two of the following skill areas: communication; self-care; social/interpersonal skills; home living; self-direction; academics; health and safety; use of community resources; and work. It is the defendant’s burden to prove he or she is mentally retarded by a preponderance of the evidence at trial. Intelligence quotients are one of the many factors that may be considered, but are not alone determinative. However, no person shall be eligible to be considered mentally retarded unless he or she has an intelligence quotient of seventy or below, as reflected by at least one scientifically recognized, scientifically approved, and contemporary intelligent quotient test. 54 P.3d 556, 567-68 (Okla.Crim.App.2002) (footnotes omitted), overruled in part on other grounds by Blonner v. State, 127 P.3d 1135, 1139 (Okla.Crim.App.2006). Mr. Hooks does not challenge Murphy’s definition of mental retardation as inconsistent with Atkins. Indeed, Murphy’s definition closely tracks the AAMR (now AAIDD) definition discussed in Atkins. See 536 U.S. at 308 n. 3, 318, 122 S.Ct. 2242. Rather, Mr. Hooks argues that the jury’s determination that he is not mentally retarded is based upon insufficient evidence, and that the OCCA’s decision to uphold that determination was contrary to, or an unreasonable application of, Atkins. 2. A sufficiency-of-the-evidence challenge in a habeas petition presents a mixed question of fact and law. Brown v. Sirmons, 515 F.3d 1072, 1089 (10th Cir.2008). “We ask whether the facts are correct and whether the law was properly applied to the facts, ‘which is why we apply both 28 U.S.C. § 2254(d)(1) and (d)(2) when reviewing sufficiency of the evidence on habeas.’ ” Id. (quoting Maynard v. Boone, 468 F.3d 665, 673 (10th Cir.2006)). The typical sufficiency challenge in a habeas petition focuses on evidence of guilt for the crime charged. In Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979), a pre-AEDPA decision, the Supreme Court held that such evidence is sufficient if, “after viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt.” In federal habeas proceedings, where a sufficiency challenge was resolved on the merits by the state courts, we have held that AED-PA “adds an additional degree of deference,” and the question becomes whether “the OCCA’s conclusion that the evidence was sufficient constituted an unreasonable application of the Jackson standard.” Diestel v. Hines, 506 F.3d 1249, 1267 (10th Cir.2007) (quoting Patton v. Mullin, 425 F.3d 788, 796 (10th Cir.2005)) (internal quotation marks omitted); see Coleman v. Johnson, — U.S. -, 132 S.Ct. 2060, 2062, 182 L.Ed.2d 978 (2012) (per curiam). We call this standard of review “deference squared.” Young v. Sirmons, 486 F.3d 655, 666 n. 3 (10th Cir.2007) (quoting Torres v. Lytle, 461 F.3d 1303, 1313 (10th Cir.2006)) (internal quotation marks omitted). In two respects, however, Mr. Hooks’s sufficiency challenge is somewhat atypical. First, the substantive law at the basis of his sufficiency challenge consists not of the “essential elements” of a state-law criminal offense, Jackson, 443 U.S. at 319, 99 S.Ct. 2781, but rather of the definition of mental retardation — a definition that, although dependent on state law (here, Murphy), ultimately has Eighth Amendment underpinnings pursuant to Atkins. See Ochoa v. Workman, 669 F.3d 1130, 1143 (10th Cir.2012) (“The liberty interest at issue in this case, the right of the mentally retarded to avoid execution, flows directly from the Eighth Amendment.”). Thus, Mr. Hooks’s sufficiency challenge inescapably requires that we consider the kinds of evidence that state courts may (or may not) rely upon in adjudicating an Atkins claim. Second, the jury in Mr. Hooks’s Atkins trial was required to determine, not whether he is guilty of an offense beyond a reasonable doubt (a question on which the State would have borne the burden of proof), but whether he is mentally retarded by a preponderance of the evidence (a question on which Mr. Hooks bore the burden of proof). The different standard of proof requires us to tailor Jackson to fit this context. We hold that the relevant constitutional standard for the state appellate court was whether, viewing the evidence in the light most favorable to the prevailing party (the State), any rational trier of fact could have found Mr. Hooks not mentally retarded by a preponderance of the evidence. See Maynard, 468 F.3d at 674. If so, Mr. Hooks’s evidentiary challenge would fail. Put a different way, if any rational trier of fact could have found that Mr. Hooks failed to establish, by a preponderance of the evidence, that he is mentally retarded, then the jury verdict may be upheld. Of course, AEDPA adds a second layer of deference to this standard. We do not directly review the jury’s verdict. AEDPA limits our gaze to “the highest state court’s resolution of a particular claim.” Alverson v. Workman, 595 F.3d 1142, 1155 (10th Cir.2010). We therefore ask whether the OCCA correctly identified the governing legal principle from Jackson and reasonably applied it to the facts of Mr. Hooks’s case. See Matthews v. Workman, 577 F.3d 1175, 1183 (10th Cir.2009) (“Because the OCCA applied the Jackson standard in deciding Mr. Matthews’s sufficiency claim on direct review, our task is limited by AEDPA to inquiring whether the OCCA’s application of Jackson was unreasonable.” (footnote omitted)). We reiterate that under both paragraphs (1) and (2) of § 2254(d), we are precluded from considering evidence not before the OCCA. See Pinholster, 131 S.Ct. at 1398 (construing 28 U.S.C. § 2254(d)(1)); 28 U.S.C. § 2254(d)(2). Based on the foregoing, we find that the OCCA’s decision, on its face, applied the correct standard of appellate review. Reviewing Mr. Hooks’s sufficiency challenge, the OCCA concluded, “Taken in the light most favorable to the prevailing party, a rational trier of fact could have found that Hooks provided insufficient evidence to show he was mentally retarded.” Hooks Atkins Appeal, 126 P.3d at 641. That is precisely what Jackson requires in order to uphold the jury’s determination in this context. See Maynard, 468 F.3d at 674. Accordingly, the OCCA’s decision was not “contrary to” clearly established federal law. Cone, 535 U.S. at 694, 122 S.Ct. 1843 (quoting 28 U.S.C. § 2254(d)(1)). “Because the OCCA applied the correct legal standard, our inquiry is limited to whether its determination that the evidence was sufficient to support the jury’s verdict was reasonable.” Young, 486 F.3d at 667. As noted, that inquiry also requires us to consider whether the OCCA, in upholding the jury’s verdict, reasonably applied Atkins to Mr. Hooks’s claim of mental retardation. 3. The parties agree that Mr. Hooks meets the second prong of Murphy’s standard for mental retardation (that the deficiencies manifested themselves before the age of eighteen). See Hooks Atkins Appeal, 126 P.3d at 641. The dispute before the jury, before the OCCA, and before us centers on whether Mr. Hooks meets the first and third prongs of the Murphy test: viz., sub-average intellectual ability, and significant limitations in adaptive functioning. a. Sub-average intellectual ability Under Murphy, a capital defendant’s IQ score is used both to establish eligibility for a mental-retardation determination and as evidence to support a finding of subaverage intellectual ability. Hooks Atkins Appeal, 126 P.3d at 640. An IQ score of 70 or below meets the threshold requirement. See id. It is also strong evidence of sub-average intelligence. See Atkins, 536 U.S. at 309 n. 5, 122 S.Ct. 2242 (“[A]n IQ between 70 and 75 or lower ... is typically considered the cutoff IQ score for the intellectual function prong of the mental retardation definition.”); id. at 316, 122 S.Ct. 2242 (suggesting that “a national consensus has developed against” the execution of “offenders possessing a known IQ less than 70”); Murphy, 54 P.3d at 568 (“Intelligence quotients are one of the many factors that may be considered, but are not alone determinative.”). Mr. Hooks has been subjected to IQ testing throughout his life, and the Atkins jury was presented with nine of his IQ scores. These scores were obtained from tests administered over a thirty-four-year period, between 1970 and 2004, and they ranged from 53 to 80. On direct appeal of the jury verdict, the OCCA concluded: The experts agreed this range of scores put Hooks in a “gray area”. The tests of 70 and below all reflected some degree of lack of cooperation on Hooks’s part, from variable attention span to refusal to respond. Two of them were obtained after Hooks suffered the trauma of an accident and his father’s death, which could have caused him to test lower than his actual intellectual level. The expert witnesses agreed that the most reliable scores were those obtained by Dr. Gelbort and Dr. Cowardin, with results of 72 and 76. Neither of these scores meets the “seventy or below” requirement in Mwrphy, although Dr. Gelbort’s results are within that range using the standard error of measurement (a five-point range on either side). Given the other testimony, it was not unreasonable for jurors to determine that the most reliable IQ evidence offered did not fall within the first prong of the Murphy definition, functioning at a significantly sub-average intellectual level. A rational trier of fact could have found that Hooks failed to meet this burden by a preponderance of the evidence. Hooks Atkins Appeal, 126 P.3d at 640—41 (footnote omitted). Mr. Hooks assails this conclusion in two ways. First, he contends that four of his IQ scores (scores of 80, 80, 61 and 76) “are of limited value and lack reliability.” Aplt. Opening Br. at 25. We shall call this group of scores the “First Group.” Second, after tossing out the above four scores, Mr. Hooks contends that the remaining five (scores of 70, 61, 57, 72, and 53) — what we shall call the “Second Group” — must be adjusted downward for a statistical phenomenon known as the Flynn Effect. After adjustment, the five scores become 63, 54, 50, 67, and 50, respectively — all well below Murphy’s threshold of 70. On this view of the evidence, Mr. Hooks argues that the OCCA’s finding that he is in a “gray area” was unreasonable. We note that the First Group includes the K-BIT score of 76 and the Second Group includes the WAIS-R score of 72, both obtained by Mr. Hooks’s own experts (Dr. Nancy Cowardin and Dr. Michael Gelbort, respectively) and deemed by the OCCA, based on the opinions of experts from both sides, to be the “most reliable” of all the IQ scores. Hooks Atkins Appeal, 126 P.3d at 640. Mr. Hooks does not contest that conclusion. With respect to the K-BIT score, he contends only that “caution” must be used in interpreting the score because Dr. Cowardin’s test was “not meant to substitute for a comprehensive intelligence test.” Aplt. Opening Br. at 26. But Dr. Cowardin was Mr. Hooks’s own expert, and her testing formed the basis for her conclusion that Mr. Hooks is mildly mentally retarded. See 4 M.R. at 116. Mr. Hooks’s other expert, Dr. Gelbort, relied on Dr. Cowardin’s report and his own evaluation to opine that Mr. Hooks is mildly mentally retarded, see 3 M.R. Tr. at 112-13, although even he admitted that Mr. Hooks fell into a “gray area,” id. at 95. Finally, the State’s expert, Dr. Terese Hall, thought the evaluations by Drs. Cowardin and Gelbort were “the best testing we have.” See 5 M.R. Tr. at 42. The OCCA found that many of the other scores, particularly those on the low end, posed reliability problems. That finding is presumed correct, and in any event, our independent review of the record confirms it. See 3 M.R. at 23, 44, 47-49 (Test, of Dr. Beck); id. at 86-88, 94-95, 174-75 (Test. of Dr. Gelbort); 4 M.R. at 111-12 (Test, of Dr. Cowardin); 5 M.R. at 19-20, 38-41 (Test, of Dr. Hall). Accordingly, it was not unreasonable for the OCCA to find the K-BIT and WAIS-R scores the “most reliable” and to accord them greater weight. Mr. Hooks asserts that the Second Group of scores, including the WAIS-R score of 72, must be downwardly adjusted for the Flynn Effect. The Flynn Effect is a phenomenon named for James R. Flynn, who discovered that the population’s mean IQ score rises over time, by approximately 0.3 points per year. Under his theory, if an individual’s test score is measured against a mean of a population sample from prior years, then his score will be inflated in varying degrees (depending on how long ago the sample was first employed) and will not provide an accurate picture of his IQ. See, e.g., Walton v. Johnson, 440 F.3d 160, 177 n. 22 (4th Cir.2006) (en banc) (“The premise of the ‘Flynn Effect’ is that IQ scores increase over time and that IQ tests that are not renormed to take into account rising IQ levels will overstate a testtaker’s IQ score.”); James. R. Flynn, Tethering the Elephant: Capital Cases, IQ, and the Flynn Effect, 12 Psychol. Pub. Pol’y & L. 170, 172 (2006) [hereinafter Flynn, Tethering the Elephant ] (“Naturally, judges want to know whether defendants were actually two standard deviations below their peers at the time they were tested and not how they rank against a group selected at some random date in the past.” (emphasis added)). See generally James R. Flynn, The Mean IQ of Americans: Massive Gains 1932 to 1978, 95 Psychol. Bull. 29 (1984). Flynn posited that a downward adjustment to scores is necessary when a test without current norms is used. See Flynn, Tethering the Elephant, supra, at 174-75. However, neither Murphy nor its progeny requires an adjustment for the Flynn Effect, see Murphy, 54 P.3d at 567-68; see also Smith, 245 P.3d at 1237 n. 6 (“[Ujnder the Oklahoma statutory scheme, the Flynn Effect, whatever its validity, is not a relevant consideration in the mental retardation determination for capital defendants.”), and the OCCA did not address its relevance on direct appeal. It mentioned it briefly on collateral review, stating that “some experts noted Hooks’s reliable score of 72 could have been slightly inflated [due to the Flynn Effect].” Hooks Atkins Collateral, slip op. at 8-9. The only Flynn Effect evidence presented to the Atkins jury came from the testimony of Dr. Gelbort, who noted that the Flynn Effect is a “well-researched and published” phenomenon, 3 M.R. Tr. at 159, and suggested that “people who talk about the Flynn Effect would argue” that certain of Mr. Hooks’s IQ scores are “a little higher than [they] ought to be,” id. at 219-22, due to the non-current population samples that were used to normalize (i.e., derive a population mean for) his scores. Mr. Hooks argues that the OCCA’s failure to account for and apply the Flynn Effect was “contrary to Atkins because it fails to deal with the real [IQ] scores.” Aplt. Reply Br. at 7. The OCCA’s failure to account for and apply the Flynn Effect was not “contrary to” or “an unreasonable application of’ clearly established federal law, 28 U.S.C. § 2254(d)(1), because the threshold requirement — the existence of clearly established federal law — is not met here. See House, 527 F.3d at 1015. Atkins does not mandate an adjustment for the Flynn Effect. Moreover, there is no scientific consensus on its validity. See Thomas v. Allen, 607 F.3d 749, 757 (11th Cir.2010) (“[T]he Flynn effect is a statistically-proven phenomenon, although no medical association recognizes its validity.”); Frank M. Gresham & Daniel J. Reschly, Standard of Practice and Flynn Effect Testimony in Death Penalty Cases, 49 Intell. & Developmental Disabilities 131, 131, 136-37 (2011) (arguing that the Flynn Effect is “a well-established psychometric fact” that should be accounted for in IQ testing, but noting the lack of a consensus in the clinical community on its use). In addition, federal and state courts are divided over the use of the Flynn Effect, and “there is no uniform consensus regarding the application of the Flynn effect in determining a capital offender’s intellectual functioning.” Thomas, 607 F.3d at 757-58 (collecting cases); see also Maldonado v. Thaler, 625 F.3d 229, 238 (5th Cir.2010) (“[N]either this court nor the [Texas Court of Criminal Appeals] has recognized the Flynn Effect as scientifically valid.”). Even if this Circuit were prepared to take a side in this debate and hold that, under Atkins, the Flynn Effect must be considered in determining whether a defendant is mentally retarded, we could not do so on habeas review. “No decision of th[e Supreme] Court ... squarely addresses the issue.... ” Wright v. Van Patten, 552 U.S. 120, 125, 128 S.Ct. 743, 169 L.Ed.2d 583 (2008) (per curiam). “Because [the Court’s] cases give no clear answer to the question presented, let alone one in [Mr. Hooks’s] favor,” id. at 126, 128 S.Ct. 743, it cannot be said that the OCCA’s failure to consider and apply the Flynn Effect is contrary to, or an unreasonable application of, clearly established federal law. We are left, then, with a number of IQ scores, some below and some above a score of 70. We do not believe this set of scores unquestionably qualifies Mr. Hooks as significantly sub-average in intellect. Given the reliability problems associated with many of the scores and the strong reliability of the scores of 72 and 76 from Mr. Hooks’s own experts, we agree that Mr. Hooks falls into a “gray area.” Hooks Atkins Appeal, 126 P.3d at 640 (internal quotation marks omitted); see also Atkins, 536 U.S. at 309 n. 5, 122 S.Ct. 2242 (“[A]n IQ between 70 and 75 or lower ... is typically considered the cutoff IQ score for the intellectual function prong of the mental retardation definition.”). A rational trier of fact could conclude from this evidence that Mr. Hooks indeed functions at a sub-average intellectual level, but it could also rationally draw the conclusion that he does not. Cf. Anderson v. Bessemer City, 470 U.S. 564, 574, 105 S.Ct. 1504, 84 L.Ed.2d 518 (1985) (“Where there are two permissible views of the evidence, the factfinder’s choice between them cannot be clearly erroneous.”). Accordingly, it was not an unreasonable application of Jackson for the OCCA to find that Mr. Hooks’s evidentiary burden was not met and to uphold the jury verdict. b. Functional limitations As an alternative basis for its holding, the OCCA also rejected Mr. Hooks’s -sufficiency-of-the-evidence challenge under the third prong of Murphy, which required Mr. Hooks to show that he has “significant limitations in adaptive functioning in at least two of [nine] skill areas.” Murphy, 54 P.3d at 567-68. After a summary of the evidence both for and against Mr. Hooks, the OCCA concluded that “a rational trier of fact could have determined that this evidence did not show significant deficits in adaptive functioning” and that Mr. Hooks had “failed to meet his burden on this issue.” Hooks Atkins Appeal, 126 P.3d at 641. Mr. Hooks argues that he satisfied Murphy’s third prong because of his deficiencies in two skills areas (communication and academics), and he assails the OCCA’s conclusion on two grounds. First, he faults the OCCA for focusing on his strengths rather than his limitations, which he contends was contrary to Atkins. Second and relatedly, he argues that a proper focus on his limitations, to the exclusion of his strengths, puts the existence of his mental retardation beyond dispute. We reject both arguments. Requiring the OCCA to focus only on Mr. Hooks’s limitations and to ignore his strengths is not clearly established federal law, and based on the evidence (limitations and strengths), a rational trier of fact could conclude that Mr. Hooks failed to satisfy the third prong of Murphy by a preponderance of the evidence. Mr. Hooks first argues that the OCCA’s focus on his strengths rather than his limitations was objectively unreasonable because it is contrary to the “holistic approach” recommended by the AAIDD, which “focuses on the individual’s limitations.” Aplt. Opening Br. at 44 (quoting AAIDD, Intellectual Disability: Definition, Classification, and Systems of Supports 94 (11th ed.2010)) (internal quotation marks omitted). He continues; ‘When the Atkins [ ] Court determined there was a national consensus that offenders meeting the clinical definition of mentally retarded could not be executed, it essentially adopted the clinical definition of the condition. Further, the focus is on deficits, not strengths, as clearly established within the clinical community and by Atkins.” Aplt. Reply Br. at 10. We are not persuaded. While Atkins is undoubtedly clearly established federal law, the precise contours of the definition of mental retardation are not. “The Supreme Court specifically left to the various states ‘the task of developing appropriate ways to enforce the constitutional restriction’ on the execution of mentally retarded criminals.” Ochoa, 669 F.3d at 1133 n. 1 (quoting Atkins, 536 U.S. at 317, 122 S.Ct. 2242). Nothing in Atkins (or Oklahoma law for that matter) requires the OCCA to ignore a defendant’s strengths in determining whether in fact he exhibits significant functional limitations in certain skill areas. Mr. Hooks bases his argument to the contrary on language in the Atkins opinion such as the following: “[Cjlinical definitions of mental retardation require ... significant limitations in adaptive skills.” Atkins, 536 U.S. at 318, 122 S.Ct. 2242 (emphasis added); see Aplt. Reply Br. at 10. This argument is unavailing. Murphy, too, requires a defendant to show “significant limitations in adaptive functioning.” 54 P.3d at 567 (emphasis added). But this is a legal standard, and whether it is satisfied depends upon the facts: What is a given defendant able and unable to do? Both strengths and deficiencies enter into this equation because they make up the universe of facts tending to establish that a defendant either has “significant limitations” or does not. Not only does Murphy not require the OCCA to focus on deficiencies to the exclusion of strengths but— most relevant to our inquiry here — neither does Atkins. Furthermore, even if the AAIDD’s “holistic approach” requires a clinician to ignore functional strengths, as Mr. Hooks contends, the clinical standard is not a constitutional command. Section 2254(d)(1) refers to “clearly established Federal law, as determined by the Supreme Court of the United States,” and as we have explained, “Supreme Court holdings” are “the exclusive touchstone for clearly established federal law.” House, 527 F.3d at 1015. The Supreme Court in Atkins could have adopted the clinical standard, but explicitly declined to do so. See Atkins, 536 U.S. at 317, 122 S.Ct. 2242; Ochoa, 669 F.3d at 1133 n. 1. We therefore conclude that the OCCA’s consideration of evidence of Mr. Hooks’s strengths was not “contrary to” or “an unreasonable application of’ Atkins. 28 U.S.C. § 2254(d)(1). That being so, Mr. Hooks’s second contention must fail. Having argued that evidence of his strengths should not be considered to support the Atkins jury’s conclusion, he selectively highlights those portions of the trial record that support his limitations in adaptive functioning. See Aplt. Opening Br. at 32-35, 39-41. But this was not the only evidence before the jury. For example: • Some experts found that Mr. Hooks communicated well and could express his thoughts and feelings clearly. 5 M.R. Tr. at 32-33, 55 (Test, of Dr. Hall). • Mr. Hooks read the Bible, 4 M.R. Tr. at 210 (Test, of Shanna Dinh); read other books in prison, id. at 125-26 (Test, of Dr. Cowardin); and could use a dictionary, id. at 125. • Mr. Hooks wrote a number of letters in which he communicated his feelings forcefully and clearly. Id. at 126-32; see State’s Exs. 1-6 to M.R. • Mr. Hooks communicated with multiple landlords and filled out rental applications. 4 M.R. Tr. at 205 (Test, of Ms. Dinh); 5 M.R. Tr. at 31 (Test, of Dr. Hall); 5 M.R. Tr. at 167 (Test, of Eric Mullenix). He also negotiated with a car salesman to obtain the price he wanted on a vehicle. 4 M.R. Tr. at 206-07 (Test, of Ms. Dinh). • Mr. Hooks lived independently and traveled to see his mother often. 2 M.R. Tr. at 184-85 (Test, of Clara Hooks); 5 M.R. Tr. at 30 (Test, of Dr. Hall); 5 M.R. Tr. at 169 (Test, of Mr. Mullenix). He talked about running errands, shopping, and having a loose muffler repaired. 5 M.R. Tr. at 167 (Test, of Mr. Mullenix). • Mr. Hooks managed his money “just fíne” and paid his bills. Id. at 31 (Test, of Dr. Hall). He frequently pawned items or sold food stamps to earn cash for groceries and items for his child. Id.; 4 M.R. Tr. at 211 (Test, of Ms. Dinh); 5 M.R. Tr. at 168 (Test, of Mr. Mullenix). • Mr. Hooks ran a prostitution ring, rented apartments for prostitutes, paid their rent, and collected money from them. 4 M.R. Tr. at 198-205 (Test, of Ms. Dinh). The evidence concerning Mr. Hooks’s behavioral limitations was controverted, and resolving the limitations question “depended heavily on the factfinders’ appraisal of witness credibility and demeanor.” Bryan v. Gibson, 276 F.3d 1163, 1172 (10th Cir.2001) (quoting Thompson v. Keohane, 516 U.S. 99, 111, 116 S.Ct. 457, 133 L.Ed.2d 383 (1995)) (internal quotation marks omitted), vacated in part on other grounds sub nom. Bryan v. Mullin, 335 F.3d 1207, 1211 (10th Cir.2003) (en banc). A rational trier of fact could have found that Mr. Hooks failed to establish, by a preponderance of the evidence, that he has significant adaptive limitations, and accordingly, the OCCA’s decision to uphold the jury verdict was not an unreasonable application of Jackson, C. Fairness of the Atkins Trial Mr. Hooks’s second claimed ground for habeas relief implicates the fundamental fairness of his Atkins trial. He asserts that a number of errors during trial violated his Fifth, Sixth, and Fourteenth Amendment rights. He puts forward the following six claims: (1) a potential juror was improperly removed for cause; (2) the trial court improperly prohibited cross-examination of Shanna Dinh, one of the State’s witnesses; (3) the State committed a Brady violation; (4) the trial court committed two state-law evidentiary errors that denied him due process; (5) his attorney at the Atkins trial was ineffective; and (6) the cumulative effect of these errors resulted in an unfair trial. Some of these claims were adjudicated on .the merits by the OCCA, and some were not. We address the appropriate standard of review in the context of each claim. We ultimately reject all six claims and conclude that Mr. Hooks is not entitled to relief on these grounds. Before proceeding, we pause to note that each of these claims is properly an “Atkins claim” subject to federal habeas review under 28 U.S.C. § 2254. See Ochoa, 669 F.3d at 1143. It is true that Atkins does not provide “definitive procedural or substantive guid[ance]” on how state courts should or must adjudicate Atkins claims. Bobby v. Bies, 556 U.S. 825, 831, 129 S.Ct. 2145, 173 L.Ed.2d 1173 (2009) (quoting Atkins, 536 U.S. at 317, 122 S.Ct. 2242). But the Supreme Court has also indicated “that state court ‘measures for adjudicating claims of mental retardation ... might, in their application, be subject to constitutional challenge.’” Ochoa, 669 F.3d at 1142 (quoting Schriro v. Smith, 546 U.S. 6, 7, 126 S.Ct. 7, 163 L.Ed.2d 6 (2005)). In our recent decision in Ochoa, we held that the Fourteenth Amendment’s due-process protections are applicable in an Atkins proceeding because “Oklahoma adopted the jury trial, with its historically attendant procedural protections, as the method to vindicate” the right of the mentally retarded to avoid execution. Id. at 1143. On that basis, we proceed to an examination of Mr. Hooks’s claims. 1. Removal of Venire Member for Cause Mr. Hooks asserts error based on the trial court’s removal for cause of a potential juror, Donna Paddock. Ms. Paddock was familiar with the clinical definition of mental retardation and suggested that if the clinical definition conflicted with the legal one, she might be unable to apply the latter impartially. See 1 M.R. Tr. at 105, 124, 159-63. The trial court granted the State’s motion and excluded her for cause. Id. at 167. On appeal, the OCCA denied Mr. Hooks’s claim of error, citing the Supreme Court’s decision in Wainwright v. Witt, 469 U.S. 412, 105 S.Ct. 844, 83 L.Ed.2d 841 (1985), and stating, “The decision to excuse a juror for cause is within the trial court’s discretion. A juror must agree to follow the law; any other response would prevent or substantially impair performance of her duties in accordance with her instructions and oath.” Hooks Atkins Appeal, 126 P.3d at 645 (footnote omitted). The OCCA noted that there was “little likelihood of conflict” between the clinical and legal definitions of mental retardation, but that “the issue” was Ms. Paddock’s duty to “follow the law, whatever it was,” which “[s]he could not do.” Id. It concluded that “[t]he trial court did not abuse its discretion in excusing her for cause.” Id. Mr. Hooks claims that the OCCA’s decision was an unreasonable application of Witt because Ms. Paddock’s views would not have prevented or substantially impaired her performance as a juror. The State counters that Witt is not clearly established federal law because “the Supreme Court has not extended [Witt] to mental retardation proceedings,” Aplee. Br. at 35, and that, in any event, the OCCA’s application of Witt was not unreasonable. At the outset, in the unique setting of an Atkins proceeding, we reject the State’s suggestion that Witt is not clearly established federal law solely because the Supreme Court has not expressly “extended” it to such proceedings. We And this argument to be unpersuasive under the rationale of our decision in Ochoa and, indeed, conclude that it is foreclosed by that precedent. See 669 F.3d at 1143. We do hold, however, that Witt cannot be read to extend to the unique “factual context,” House, 527 F.3d at 1016 (emphasis added), of Mr. Hooks’s claim, and for that reason, there is no clearly established federal law that allows us to evaluate the claim. In Witherspoon v. Illinois, 391 U.S. 510, 522, 88 S.Ct. 1770, 20 L.Ed.2d 776 (1968), the Supreme Court held that venire members in a capital case may not be excused for cause “simply because they voice[] general objections to the death penalty.” Such exclusion violates a capital defendant’s Sixth and Fourteenth Amendment right to an impartial jury, for it empanels “a jury uncommonly willing to condemn a man to die.” Id. at 521, 88 S.Ct. 1770. In Witt, the Court, building upon Witherspoon, set forth “the proper standard for determining when a prospective juror may be excluded for cause because of his or her views on capital punishment.” 469 U.S. at 424, 105 S.Ct. 844. “That standard is whether the juror’s views would ‘prevent or substantially impair the performance of his duties as a juror in accordance with his instructions and his oath.’ ” Id. (quoting Adams v. Texas, 448 U.S. 38, 45, 100 S.Ct. 2521, 65 L.Ed.2d 581 (1980)). In Gray v. Mississippi 481 U.S. 648, 668, 107 S.Ct. 2045, 95 L.Ed.2d 622 (1987), the Court affirmed these principles, holding that the erroneous “Witherspoon exclusion” of a qualified juror in a capital case entitles the defendant to automatic reversal of his sentence. Important as it is, the Witherspoon-Witt rule is a narrow one. First, it does not apply outside the context of capital sentencing. See Lockhart v. McCree, 476 U.S. 162, 183, 106 S.Ct. 1758, 90 L.Ed.2d 137 (1986) (“We reject [the] suggestion that Witherspoon and Adams have broad applicability outside the special context of capital sentencing....”); United States v. Prince, 647 F.3d 1257, 1264 (10th Cir.2011) (“The Court has never extended this doctrine beyond the death penalty context.”). Second, and more importantly for present purposes, the Supreme Court has never applied the rule to the removal of a venire member for reasons other than the member’s “views on capital punishment.” Witt, 469 U.S. at 424, 105 S.Ct. 844; cf. Ross v. Oklahoma, 487 U.S. 81, 87-88, 108 S.Ct. 2273, 101 L.Ed.2d 80 (1988) (“We decline to extend the rule of Gray beyond its context: the erroneous ‘Witherspoon exclusion’ of a qualified juror in a capital case. We think the broad language used by the Gray Court is too sweeping to be applied literally, and is best understood in the context of the facts there involved.” (footnote omitted)). Thus, as our sister circuits have recognized, apart from “questions of death penalty scruples,” exclusion of a particular venire member does not ordinarily entitle a defendant to relief because “[a] defendant has no constitutional or other right to the service of a particular juror.” United States v. Joseph, 892 F.2d 118, 124 (D.C.Cir.1989); see Jones v. Dretke, 375 F.3d 352, 355 (5th Cir.2004). Where a potential juror is excused for reasons other than her views on the death penalty, even an erroneous exclusion is not constitutional error “so long as the jury that sits is impartial.” Jones, 375 F.3d at 355 (quoting United States v. Martinez-Salazar, 528 U.S. 304, 313, 120 S.Ct. 774, 145 L.Ed.2d 792 (2000)) (internal quotation marks omitted); see also United States v. Perez, 387 F.3d 201, 208 (2d Cir.2004) (“Not every error during voir dire compels a new trial, and outside of the limited realm that Gray carved out for capital sentencing, the inquiry we ordinarily engage in asks whether an error of exclusion resulted in prejudice to the defendant. Since appellant does not contest that the jury ultimately impaneled was fair and impartial, his allegation of error does not implicate his constitutional right to a fair trial.”); United States v. Brooks, 175 F.3d 605, 606 (8th Cir.1999); United States v. Padilla-Mendoza, 157 F.3d 730, 734 (9th Cir.1998). In light of the foregoing, we hold that there is no clearly established federal law entitling Mr. Hooks to relief. The Witherspoonr-Witt rule applies only in the capital-sentencing context, and only when a venire member is erroneously removed for cause “because of his or her views on capital punishment.” Witt, 469 U.S. at 424, 105 S.Ct. 844. Here, the venire member, Ms. Paddock, was excused not “because of ... her views on capital punishment,” id., but because she professed an apparent inability to set aside her clinical training and adhere to the legal definition of mental retardation. This is not the fact pattern implicated by Witherspoonr-Witt. Accordingly, Mr. Hooks’s impartial-jury claim must focus “on the jurors who ultimately sat.” Ross, 487 U.S. at 86, 108 S.Ct. 2273. However, since he “does not contest that the jury ultimately impaneled was fair and impartial, his allegation of error does not implicate his constitutional right to a fair trial.” Perez, 387 F.3d at 208. The claim thus fails at the threshold for lack of clearly established federal law, and we need not evaluate the OCCA’s resolution of it. See House, 527 F.3d at 1018 (“The absence of clearly established federal law is dispositive under § 2254(d)(1).”). 2. Cross-Examination of Shanna Dinh At the Atkins trial, Shanna Dinh, a witness for the State and a former friend of Mr. Hooks, testified at length about Mr. Hooks’s daily routine, numerous girlfriends, running of a prostitution ring, negotiation with landlords and a car salesman, and meticulous cleaning habits, among other things. See 4 M.R. Tr. at 194-215. On cross-examination, counsel sought to impeach Ms. Dinh’s credibility with prior inconsistent statements, including statements she made at Mr. Hooks’s original trial in 1989. The most notable inconsistency concerned Ms. Dinh’s living arrangements. She claimed at the 1989 trial to have lived with Mr. Hooks “for a couple of months,” 2 Trial Tr. at 413 (Test, of Ms. Dinh), but claimed at the 2004 Atkins trial to have lived with him for years, see 4 M.R. Tr. at 197-98. Mr. Hooks avers that the trial court “prohibited all inquiry” into this and other alleged inconsistencies, thereby denying him his right to confrontation under the Sixth and Fourteenth Amendments. Aplt. Opening Br. at 53. “The Confrontation Clause of the Sixth Amendment guarantees the right of an accused in a criminal prosecution ‘to be confronted with the witnesses against him.’ ” Delaware v. Van Arsdall, 475 U.S. 673, 678, 106 S.Ct. 1431, 89 L.Ed.2d 674 (1986). “Confrontation means more than being allowed to confront the witness physically.” Davis v. Alaska, 415 U.S. 308, 315, 94 S.Ct. 1105, 39 L.Ed.2d 347 (1974). Central to the Clause’s purpose is “securing] for the opponent the opportunity of cross-examination.” Van Arsdall, 475 U.S. at 678, 106 S.Ct. 1431 (emphasis omitted) (quoting Davis, 415 U.S. at 315—16, 94 S.Ct. 1105) (internal quotation marks omitted). The right of confrontation through cross-examination is not absolute, however. “[TJrial judges retain wide latitude insofar as the Confrontation Clause is concerned to impose reasonable limits on such cross-examination based on concerns about, among other things, harassment, prejudice, confusion of the issues, the witnesses] safety, or interrogation that is repetitive or only marginally relevant.” Id. at 679, 106 S.Ct. 1431. And “the Confrontation Clause guarantees an opportunity for effective cross-examination, not cross-examination that is effective in whatever way, and to whatever extent, the defense might wish.” Delaware v. Fensterer, 474 U.S. 15, 20, 106 S.Ct. 292, 88 L.Ed.2d 15 (1985). The OCCA rejected Mr. Hooks’s Confrontation Clause claim, resting its conclusion on the ground that, while Ms. Dinh may not have truthfully testified about her living arrangements, “[Mr.] Hooks offers no evidence to suggest that [Ms. Dinh’s] testimony regarding her observations during the time she did spend with him were inaccurate.” Hooks Atkins Appeal, 126 P.3d at 643. In light of our ultimate disposition of this challenge, it suffices for us to assume without deciding that the Supreme Court’s Confrontation Clause jurisprudence is clearly established law in the Atkins context. Cf. Wilson v. Sirmons, 536 F.3d 1064, 1111 (10th Cir.2008) (“[W]e have recently stated that it is far from clear whether the Confrontation Clause even applies at capital sentencing proceedings.” (quoting United States v. Barrett, 496 F.3d 1079, 1099 (10th Cir.2007)) (internal quotation marks omitted)), rehr’g granted on other grounds, 549 F.3d 1267 (10th Cir.2008). Operating on that assumption, we nonetheless hold that the OCCA’s ruling was an erroneous and unreasonable application of the Supreme Court’s Confrontation Clause precedents. As the Court explained in Davis, Cross-examination is the principal means by which the believability of a witness and the truth of his testimony are tested. Subject always to the broad discretion of a trial judge to preclude repetitive and unduly harassing interrogation, the cross-examiner is not only permitted to delve into the witness’ [s] story to test the witness’[s] perceptions and memory, but the cross-examiner has traditionally been allowed to impeach, i.e., discredit, the witness. 415 U.S. at 316, 94 S.Ct. 1105 (emphases added). Mr. Hooks sought to impeach Ms. Dinh for this very purpose — not to impugn the accuracy of her specific observations of his behavior, but to discredit her generally and highlight her capacity for untruthfulness. The OCCA rejected Mr. Hooks’s claim because his impeachment evidence did not counter the accuracy of specific observations made by Ms. Dinh. That ruling, however, reflects an incomplete understanding of the Confrontation Clause’s protective sweep. The Clause secures far more than the right to challenge the accuracy of specific aspects of a witness’s testimony. It entitles a defendant to “confront” the witness, “to expose to the jury the facts from which jurors ... could appropriately draw inferences relating to the reliability of the witness.” Kentucky v. Stincer, 482 U.S. 730, 738, 107 S.Ct. 2658, 96 L.Ed.2d 631 (1987) (omission in original) (quoting Davis, 415 U.S. at 318, 94 S.Ct. 1105) (internal quotation marks omitted). The OCCA’s rationale for rejecting Mr. Hooks’s Confrontation Clause claim was an unreasonable application of the Supreme Court’s precedents. Because the OCCA unreasonably applied (what w