In the case of Demosthenes et al. v. Baal et al., 1989, the U.S Supreme Court ruled in favor of the state's right to execute a prisoner over his claim that he was incompetent due to mental illness. The court held that it is constitutional for states to establish their own standards for determining whether a condemned inmate has sufficient mental capacity to understand his death sentence and its implications. In this particular case, Alvin Bernard Ford had been sentenced to death in Florida but later developed schizophrenia while on death row. His lawyers argued that executing him would be cruel and unusual punishment because he could not comprehend why he was being put to death or what dying meant due to his severe mental illness.

In the dissenting opinion for Demosthenes v. Baal, Justice Brennan, joined by Justices Marshall and Blackmun, argued that the majority's decision to deny a stay of execution was based on an incorrect interpretation of federal law. They contended that it is not necessary for a defendant to show he has exhausted all state remedies before seeking federal habeas corpus relief if there are circumstances making such exhaustion ineffective to protect his rights. The dissenters believed that this case presented such circumstances because Baal had been denied access to psychiatric assistance in preparing his insanity defense at trial and during post-conviction proceedings. They also criticized the majority's reliance on procedural default rules as grounds for denying relief, arguing these should be applied flexibly in capital cases where substantial constitutional claims are at stake.