The Court has struggled for well over a century with the issue of who has final authority to define what is a "crime" for purposes of applying procedural protections guaranteed by the Constitution in criminal cases. Just as labeling an action "civil" may allow the government to circumvent constitutional criminal procedure entirely, so labeling a fact an "affirmative defense" or a "sentencing factor" instead of an element of the offense may allow the government to escape constitutional criminal procedure selectively, bypassing the burden of proof, pleading, and jury requirements that would otherwise apply to an offense element. In its decision in Apprendi v. New Jersey, the Court put to rest one aspect of this ongoing battle about the significance of labels, declaring that any fact, other than a prior conviction, that increases the penalty for an offense beyond the prescribed statutory maximum must be submitted to a jury and proven beyond a reasonable doubt. But even as Apprendi settled one dispute, it uncovered others. The Court also recognized the possibility that legislatures might simply amend some of the many criminal statutes affected by this rule, in order to avoid full-blown trial adjudication of sentence-enhancing facts. Our examination of the response by every state legislature and Congress to seven major Supreme Court decisions allowing a change in substantive criminal law to effectuate a relaxation in procedures indicates that there will, in fact, be post-Apprendi evasion. Stating only that any effort to avoid the Apprendi rule by redrafting criminal statutes will be subject to "constitutional scrutiny," the Court invited litigation over the constitutionality of substantive criminal law, but offered few clues about what shape that constitutional scrutiny should take. We take up this challenge. Drawing guidance from the rich and varied history of constitutional regulation of the substantive criminal law under many different constitutional provisions (including the Court's most recent efforts to police ...