Perhaps it is because, in contrast, there's evidence that opinion is shifting away from executing the retarded that the Supreme Court is revisiting that issue at last. The justices ruled only 12 years ago that it was constitutionally just fine to kill the retarded. At the time, only two states forbade the practice, but now 13 do and Congress has barred such executions for federal crimes. The court recently heard the claim in a Texas case that juries should be told clearly they can take a convict's retardation into account in deciding the sentence. In a pending North Carolina case, the justices will reconsider the very constitutionality of executing the retarded.
Executions do no deter crime.
Their knowledgeable supporters no longer even bother to try to make that case. The evidence is definitive. The execution of juveniles and the retarded have, to credit them, typically nothing better than the crudest political opportunism, the clamor of grandstanding candidates. Bill Clinton, to prove his capital punishment bona fides when he was first running for president, flew to Arkansas to be present for the execution of a man so profoundly brain damaged he wanted to save the dessert from his last meal to have after his execution. Justice is shamed when we kill the uncomprehending and the incompetent in its name.