Enforcing federalism is most commonly thought to involve the search for a
constitutional delegation of substantive power. Although in modern times the substantive power might be overlapping or shared authority, federalism enforcement proceeds from a determination about the site of substantive power. This conception of federalism enforcement preserves the Constitution’s commitment to fractionated authority by determining whether power is legitimately possessed. Thus we understand significant federalism disputes in our age as framed by whether Congress has the authority to enact comprehensive health care reform legislation, or whether Congress
has exceeded its authority in reenacting the Voting Rights Act’s preclearance requirements. Federalism enforcement as allocation also underwrites much federal courts doctrine. We ask whether Congress has the authority to commandeer state courts, or whether states have the right to close their doors to federal claims.

This Article challenges allocation as the exclusive method of federalism enforcement. By focusing on the issue of state court duties to federal claims, this Article asserts that federalism enforcement includes an alternative to allocation—relational federalism enforcement. Relational federalism enforcement is understood as the judicial mediation of the interaction of the national government and state governments that goes beyond merely invalidating particular practices as beyond the scope of power possessed by a particular institutional actor. Relational federalism enforcement is grounded in the recognition that the Constitution establishes an enduring relationship
between states and the national government. Following from this, relational federalism enforcement relies on behavioral norms, imposed on both states and the national government, that are consistent with the enduring nature of their interaction under the constitutional structure of federalism. In contrast to several leading scholars who seek to justify state court duties to federal claims in relational terms, this Article argues that any duties imposed on state courts with respect to federal claims are better understood by looking through a relational lens. Further, this framework has far-reaching consequences
for our understanding of other aspects of judicial federalism—abstention and
Supreme Court appellate review of state court decisions—and legislative federalism—preemption, Dormant Commerce Clause and Spending Clause controversies.