Federal Lawmaking and the Role of Structure in Constitutional Interpretation

In a recent article published in this Review,' I argued that the Supreme Court's decision in Erie Railroad Co. v. Tompkins2 is best understood as resting on the Supremacy Clause and the associated political and procedural safeguards of federalism built into constitutionally prescribed lawmaking procedures. On this view, the Constitution requires federal courts to follow state law unless the "Constitution," "Laws," and "Treaties" of the United States supply a contrary rule of decision.3 I wrote that piece to address the frequent contention that, notwithstanding the Court's repeated invocations of the Constitution, Erie does not actually rest on constitutional grounds. In a pair of subsequent articles, Professor Craig Green renews this suggestion4 and denies that the Supremacy Clause provides a basis for the decision in Erie or otherwise limits federal lawmaking.5 Although he makes an important contribution to a growing body of Erie-related scholarship, Green gives insufficient weight to the fundamental role that the Supremacy Clause plays in our federal system. Properly understood, Erie implicates both separation of powers and federalism. The former concerns the extent to which