The Supreme Court's 1992 abortion decision, Planned Parenthood v. Casey, an the Due Process liberty cases of which it is among the most recent, can be fully understood only by attention to the often-neglected common law dimension of American constitutionalism. The fracture on the Court in this line of cases follows a severing of two elements of common law adjudication: the rule of precedent, on the one hand, and the authority of tradition, on the other. The authors of the joint opinion in Casey craft a rationalized rule of precedent in the manner of the modern reinterpreters of the common law, such as Justices Holmes and Cardozo. The dissenters, by contrast, here and in related cases, seek to recover the legal status of tradition in constitutional interpretation.