"With Douglas, Brennan, and Stewart provoking us to view Papachristou and Roe together-whether for good or ill-implications beyond those for fundamental-rights doctrine come into focus. In particular, placing the two cases in conversation provides additional fodder for Stuntz’s analysis of the relative absence of constitutional criminal law. Because we usually consider Griswold, Loving, Eisenstadt, Roe, and their ilk as substantive due process or fundamental rights (or even equal protection) cases, we fail to see them as criminal law cases. But they were. They were all cases in which the Court was placing substantive limits on the extent to which the criminal law could be used as a mechanism of morals regulation."