It’s an interesting question, and it’s the issue presented in a pending cert petition at the Supreme Court in the case of Delling v. Idaho, recently filed by Jeffrey Fisher of the Stanford Supreme Court Litigation Clinic. Stephen Morse of Penn and Richard Bonnie of UVA put together an amicus brief of 52 law professors asking the Court to grant cert and then reach the conclusion on the merits that the Constitution does require an insanity defense to be available. I don’t know what I think of the issue on the merits, but as a criminal law professor I’d love to see cert granted. It’s a great issue, and there is an unfortunate lack of authority one way or the other on the constitutional floor of many important criminal law doctrines.
Thanks to Prawfs for the link.