Implementing enumeration.

Author:Coan, Andrew
Position:Enumerated legislative powers limitations


The enumeration of legislative powers in Article I of the U.S. Constitution implies that those powers must have limits. This familiar "enumeration principle" has deep roots in American constitutional history and has played a central role in recent federalism decisions of the U.S. Supreme Court. Courts and commentators, however, have seldom rigorously considered what follows from embracing it. The answer is by no means straightforward. The enumeration principle tells us that federal power must be subject to some limit, but it does not tell us what that limit should be. Nor does it tell us how the Constitution's commitment to limited federal power should be balanced against its equally clear commitment to effective national government. Finally, the enumeration principle sheds no light on the difficult questions of judicial competence and capacity raised by a principle that requires judges to craft limits on federal power out of whole cloth. These difficulties may or may not be surmountable, but no rigorous attempt to implement the enumeration principle can avoid grappling with them.


The enumeration principle is familiar to all first-year constitutional law students. Conventionally understood, it holds that the enumeration of legislative powers in Article I of the U.S. Constitution implies that those powers must be limited. (1) Put in reverse, the powers of Congress cannot amount to the equivalent of the general legislative authority--or "police power"--enjoyed by the states. Otherwise, why would the Framers have bothered drafting such a careful and circumscribed list of legislative powers?

So formulated, the enumeration principle is a special case of the expressio unius canon: to express one thing (enumeration) is to exclude the other (a general federal police power). (2) It can also be understood as a special case of the closely related canon against surplusage. To construe federal legislative power as the equivalent of a general police power would render the careful enumeration of powers in Article I purely gratuitous--in the language of the cases, mere "surplusage." (3) Or so the argument goes.

There are good reasons that the enumeration principle is so familiar. It has deep roots in American constitutional history. (4) More recently, it has played a central role in justifying the only limits the Supreme Court has enforced on the federal commerce power since the New Deal--the economic/noneconomic distinction established in United States v. Lopez (5) and the activity/inactivity distinction endorsed by five Justices in NFIB v. Sebelius. (6) The enumeration principle was also at the heart of the challengers' arguments in Gonzales v. Raich, which convinced three Justices that the regulation of homegrown, state-sanctioned medical marijuana was beyond the commerce power of Congress. (7) If NFIB marks the arrival of a new "constitutional gestalt," as one leading commentator has suggested, (8) the enumeration principle is unquestionably central to the vision of American federalism that gestalt embraces.

The most interesting recent challenge to this vision comes from Richard Primus. (9) The enumeration of specific federal powers in the U.S. Constitution may "presuppose[] something not enumerated," he argues, but it requires only that Congress be limited to those powers enumerated in Article I. (10) Depending on the state of the external world, it is entirely possible that the sum of those powers will be indistinguishable from a general police power. (11) In particular, given the highly integrated character of the modern American economy, the Commerce and Necessary and Proper Clauses may, in 2016, be best read to encompass virtually all human activity. (12) If that is the case, Primus contends, nothing in the text, history, or structure of the Constitution justifies the imposition of artificial "internal limits" on Congress's powers. (13)

Primus may be right, but he is a clear outlier. The Supreme Court's post-1995 federalism decisions have many academic critics, but few take serious issue with the enumeration principle. None of the dissenting Justices in those cases has disputed its validity. Like the correctness of Brown v. Board of Education, (14) acceptance of the enumeration principle remains something close to a prerequisite for admission to the American constitutional mainstream. All of the sitting Justices of the U.S. Supreme Court appear to embrace it. (15) Even Primus recognizes the conventional understanding of the enumeration principle as a "longstanding orthodoxy" with a venerable pedigree in American constitutional thought. (16)

Taking this orthodoxy as given, this Article asks what follows from accepting it. How, precisely, does the enumeration principle bear on the resolution of particular constitutional challenges to particular exercises of congressional power? How, in other words, should the Supreme Court go about implementing that principle? Surprisingly, courts and commentators have seldom rigorously considered this important question. The answer is by no means straightforward.

There are three essential difficulties. First, if the enumeration principle tells us that Congress's power must be subject to some internal limit, it does not tell us what that limit should be. Put differently, the set of internal limits consistent with the enumeration principle is infinite--or nearly so. Some additional justification is therefore needed to defend any particular limit.

Second, the enumeration principle does not tell us how to balance the Constitution's commitment to internal limits with its equally apparent commitment to effective national government. Put differently, the enumeration principle focuses exclusively on the risk of Type I errors (giving Congress too much power) while ignoring the risk of Type II errors (giving Congress too little power). This problem is made especially acute by the fact that the enumeration principle does no serious analytic work unless the sum of Congress's enumerated powers is otherwise--that is, without reference to the enumeration principle--best interpreted as equivalent to a general police power.

Third, the enumeration principle sheds no light on the questions of judicial competence and capacity raised by a principle that requires judges to craft internal limits from whole cloth, when the best reading of the constitutional text would otherwise render federal power free from such constraints. What do Supreme Court Justices know about the optimal balance of state and federal power in the twenty-first century? The categorical tests they have embraced thus far--distinguishing between economic and noneconomic activity and between activity and inactivity--are not encouraging. Neither of these distinctions is even a fair proxy for "what is truly national and what is truly local." (17)

It is no accident, however, that the Supreme Court has embraced such crude categorical rules. A more sensitive standard, which might permit the Court to more reliably distinguish the national from the local, would generate substantial uncertainty, casting a pall of constitutional doubt over a broad swath of federal legislation. Because the Supreme Court reviews nearly every lower court decision invalidating a federal law, such an approach might well invite more litigation than the Court could handle. (18)

Any attempt to implement the enumeration principle therefore threatens to impale the Court on the horns of a dilemma. It can either settle for a crude categorical rule, which poorly serves the underlying purposes of American federalism, or embrace a more sensitive standard and risk overwhelming its own limited capacity, which it has historically been unwilling to do. (19) Compared to these alternatives, abandoning the enumeration principle does not look so bad. This, at any rate, is the challenge that proponents of that principle must overcome.

I do not propose to resolve these difficulties in this brief Article. However, I do propose that they are worth grappling with. Indeed, for anyone who embraces the enumeration principle as conventionally understood, they are unavoidable. More generally, these difficulties highlight a surprisingly little-remarked challenge of interpreting a 225-year-old constitution. Not only can the passage of time change the practical meaning of such a constitution (20)--or render it clumsy and outdated, as critics have long urged. (21) The passage of time can also place such a constitution--and perhaps does place the U.S. Constitution--at war with itself. This possibility deserves more attention than it has received to date.


    What follows from the enumeration principle conventionally understood? At least since 1995, a majority of the U.S. Supreme Court has thought the answer to be straightforward. (22) Any interpretation of Congress's enumerated powers that would render them without internal limit--that is, the effective equivalent of a general police power--must be rejected. Conversely, the proper interpretation of Congress's enumerated powers--individually and in the aggregate--must impose some internal limit on those powers.

    This was the essential logic behind the economic/noneconomic distinction announced in Lopez and reaffirmed in United States v. Morrison. In defending the Gun-Free School Zones Act and the Violence Against Women Act, respectively, the government relied on the "substantial effects test," which, at the time, permitted Congress to regulate any activity it rationally believed, in the aggregate, to have a substantial effect on interstate commerce. (23) As a matter of existing doctrine...

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