Whether the Sixth Circuit correctly applied this court's guidance from Miller-El v. Cockrell, 537 U.S. 322, 326 (2003) and Buck v. Davis, 137 S. Ct. 759 (2017) regarding Petitioner's Request for a Certificate of Appealability. Despite this guidance, this petition presents the following questions:

1. Did the Sixth Circuit impose an unduly burdensome Certificate of Appealability (COA) standard in contravention of precedent?

2. Did the Sixth Circuit improperly justify its denial of petitioner's COA on the issues presented by adjudication of the actual merits of petitioner's case instead of properly limiting its inquiry into a threshold examination of the merits of the case and assessing whether the issues presented by petitioner were debatable?

3. Did the Sixth Circuit improperly ignore relevant facts in fashioning their determination that the issues in petitioner's case are not debatable?

Whether the Eighth Amendment's prohibition on cruel and unusual punishment prohibits the execution of a prisoner who was intellectually disabled at the time of the offense