The American constitutional order embodies a tension between two irreconcilable ideas. "Enumerationism" holds that federal powers are limited to those expressly enumerated in the Constitution, plus whatever implied powers are necessary and proper to execute them. What I call "capable federalism" asserts that the Constitution creates a national government fully empowered to address all national problems. Enumerationism rejects the idea that the federal government has general powers, or that it has implied powers of equal or greater dimension than those expressly listed. Capable federalism is a general power by definition, and it is fully compatible with formal recognition of implied "great" powers. Although the two theories are incompatible, our constitutional doctrine tries to harmonize them by claiming to adhere to enumerationism while evading its strictures. We find various constitutional tricks and cheats to accommodate the "structural imperative" that any federalist system must ensure that all social problems can be addressed by at least one level of government. Still, an ideological overlay of enumerationism continues to suppress any formal recognition of capable federalism.
This article argues that enumerationism is an ideology far more than it is a viable constitutional theory. Lacking a compelling claim to our constitutional fidelity as a matter of text or history, enumerationism is also lacking as a principle. Its purported logical premises"that a limited grant of power requires enumeration, and that an enumeration must always be interpreted as exclusive"are both false. The inability of enumerationism to explain implied powers undermines its logical consistency. And by requiring as an axiom that there be some regulatory gap"identifiable subjects of national regulatory concern that cannot be adequately addressed by any level of government in our federal system"enumerationism imposes social costs without a countervailing justification. Not surprisingly, our constitutional practice, over the long run from ratification to the present, has been reflective of capable federalism: some way will be found to accommodate a federal power to address national legislative problems.
