Final answer:
In McCleskey v. Kemp, the Supreme Court held that racial disparities in death penalty cases alone cannot prove discrimination against the Equal Protection Clause. The Court has consistently narrowed the application of the death penalty in cases such as Gregg v. Georgia and Atkins v. Virginia.
Step-by-step explanation:
In the case of McCleskey v. Kemp, the United States Supreme Court ruled that racial disparities in the imposition of the death penalty do not, by themselves, constitute a violation of the Equal Protection Clause. Thus, the correct answer is:
b) Racial disparities in death penalty cases are not enough to prove discrimination.
The Supreme Court has addressed several issues surrounding the death penalty. For instance, in Gregg v. Georgia, the Court affirmed the constitutionality of Georgia's new death penalty statute, which adequately narrowed the class of defendants eligible for the death penalty. This decision effectively ended the moratorium on executions that started with Furman v. Georgia, where the Court held that arbitrary and inconsistent imposition of the death penalty was cruel and unusual punishment.
Other significant cases include Kennedy v. Louisiana, which ruled that the death penalty is unconstitutional in cases that do not involve murder or crimes against the state, such as treason. Additionally, the Supreme Court ruled that imposing the death penalty on individuals with intellectual disabilities (Atkins v. Virginia) or on those who were minors at the time of the crime is considered cruel and unusual punishment.