As Chris Walker generously highlighted in an earlier post, I have written a forthcoming article on a separation-of-powers question I think has received insufficient attention: the extent of Congress’s authority to control executive constitutional authorities through restricted or conditional appropriations.

For those interested, I have summarized my main arguments in prior posts on the Take Care blog here and here. In this guest post, I want to address an argument that Professor Gillian Metzger recently advanced (among other claims) in her powerfully argued Harvard Law Review foreword this fall: the argument that Congress holds (as Metzger puts it) “a duty to provide the resources necessary for the executive branch to adequately fulfill its constitutional functions.”

On Metzger’s account, “[i]t follows” from the President’s constitutional obligation to “take Care that the Laws be faithfully executed” that “the administrative capacity the President needs in order to satisfy the take care duty is also required.” If correct, this view could have quite significant implications for the balance of power between Congress and the executive branch. By way of illustration, President Trump recently indicated, based on similar logic, that he may disregard congressional limitations on federal marijuana enforcement because such limitations infringe upon his constitutional responsibility for faithful execution of federal law.

I am unpersuaded. While the President holds an obligation to ensure faithful execution of the laws, Congress holds sole authority to appropriate resources for that power’s exercise. This authority, moreover, has proven in practice to be one of the most significant constitutional constraints on modern executive governance. In our era of presidential administration and partisan distrust, cutting these purse strings could be perilous indeed.

In general, for reasons I explain at greater length in the article, the constitutional structure supports grouping presidential authorities in two general categories. Some presidential powers are “resource-independent,” in the sense that the President could exercise them on his own without any supporting appropriation. The President, for example, could veto legislation, pardon federal offenders, and appoint officers whether or not Congress provide any resources to support the exercise these powers. Given that the President requires no help from Congress to exercise these powers, it stands to reason that Congress cannot use its control over resources to directly dictate how such powers are in fact exercised.

But the President’s responsibility for faithful execution (like his authority to order military action, among other things) has an entirely different character. Its exercise is thoroughly dependent on Congress’s provision of resources.

Why? For one thing, the Take Care Clause’s text itself presumes presidential dependence on enforcement resources otherwise made available by Congress. The Clause, after all, grants the President no personal authority to enforce the law; it instead only obligates him to ensure that those laws “be faithfully executed.” Furthermore, appropriations statutes, including whatever limitations they provide on specific activities or overall funding, are themselves laws the President must execute pursuant to this duty of faithful execution.

Nor is Congress’s appropriations power the only basis for this authority. Congress also holds authority, under the Appointments and Necessary and Proper Clauses, to establish offices, vest them with particular powers, and enact laws limiting those powers’ exercise. Much as establishing an office subject to Senate confirmation carries the inevitable consequence that future Senates will have some control over appointments, limiting enforcement of particular laws to specified public officials carries the inevitable consequence that Congress will have continuing control, through future appropriations levels, over how those laws are enforced.

It is true that Presidents (like Trump) have periodically claimed otherwise. President Rutherford Hayes, for example, objected on constitutional grounds to legislation that would “deprive the executive department of the means to execute laws which are not repealed, which have not been declared invalid, and which it is therefore the duty of the executive and of every other department of Government to obey and to enforce.” In practice, however, so far as I am aware, past presidents have not actually defied significant specific funding limitations on enforcement activities.

At the very least, the great weight of historical practice counts against viewing federal enforcement as a resource-independent executive power. Why, after all, does the federal government “shut down” when annual appropriations lapse? Precisely because Congress’s power of the purse entails power to deny funding to carry out previously conferred authorities.

Indeed, today this assumption of resource dependence is so deeply entrenched that it has likely shaped the character of the substantive laws themselves. In federal criminal law, Congress has long legislated against an expectation that resource shortfalls will necessitate extensive enforcement discretion, thus preventing application of overbroad prohibitions with full rigor. Immigration law appears to reflect the same troubling dynamics: Congress has enacted ever harsher restrictions against an expectation that enforcement discretion will in practice moderate the law’s application.

In administrative law generally, the mismatch between regulatory aspirations and actual enforcement capacity is so pervasive that the Supreme Court famously held that agency nonenforcement decisions are presumptively unreviewable. Against this backdrop, a suggestion that Congress must provide “sufficient” resources for law enforcement in any given area—and, by implication, that the President might permissibly disregard congressional funding limitations—could carry quite alarming implications for regulated parties.

In important ways, the current structure of federal governance inverts the classical separation of powers. As a result of accreted historical practice and past statutory delegations (in many cases enacted during periods of greater political cohesion), the executive branch holds considerable power of initiative in setting national policy. Congress has increasingly assumed a reactive role.

For that very reason, however, Congress’s power over appropriations, along with its other reactive powers (explored at length in a notable recent book by Josh Chafetz), may be more important than ever to maintaining responsive and accountable government—and perhaps even to maintaining federal administration’s overall legitimacy. We should be wary of arguments that weaken this congressional power’s hold on the executive branch.

Zachary Price is an Associate Professor of Law at UC Hastings College of Law. A version of this essay is cross-posted on the Take Care Blog.