When a state habeas court denies a petitioner relief on a federal constitutional claim by imposing a higher burden than is required by federal law, should a federal court conduct de novo review on the grounds that the state court's decision is not an 'adjudicat[ion] on the merits' within the meaning of 28 U.S.C. § 2254(d)?

Questions Presented 1. When a state habeas court denies a petitioner relief on a federal constitutional claim his claim by imposing a higher burden than is required by federal law, should a federal court conduct de novo review on the grounds that the state court’s decision is not an “adjudicat[ion] on the merits” within the meaning of 28 U.S.C. § 2254(d)? 2. When a state habeas court denies a petitioner relief on a federal constitutional claim his claim by imposing a higher burden than is required by federal law, is the state court's decision an “unreasonable application of[] clearly established Federal law” within the meaning of 28 U.S.C. § 2254(d)(1)? 3. When a death row inmate raises a successive claim in state court that he is ineligible for execution pursuant to this Court’s decision in Atkins v. Virginia, 536 U.S. 304 (2002), and its progeny, is a state court’s decision denying relief on the basis the inmate has not presented “clear and convincing evidence” of intellectual disability a violation of either the Eighth Amendment or the Fourteenth Amendment’s Due Process Clause? 4. When state requires that death-sentenced inmates who seek relief on Atkins claims in successive petitions demonstrate intellectual disability by “clear and convincing evidence,” is there “an absence of available State corrective process” within the meaning of 28 U.S.C. 2254(b)(1)(B)(1)? ii