From the abstract for Zachary Price, Funding Restrictions and Separation of Powers, 71 Vanderbilt Law Review 357 (2018):
Congress’s “power of the purse”—its authority to deny access to public funds—is one of its most essential constitutional authorities. A crucial check on executive overreaching, it may provide authority to stop presidents in their tracks. Yet Congress and the executive branch have developed widely divergent views on the scope of this authority. During the Obama Administration, sharp conflicts over this issue arose in areas of acute policy conflict, including climate change, prisoner transfers, proposed closure of detention facilities at the Guantanamo Naval Base, and federal marijuana enforcement. Many planned initiatives of the Trump Administration—from immigration enforcement, to renegotiation of trade deals, to military operations against Islamic terrorists or other foreign adversaries—could present analogous questions. Despite the issue’s contemporary salience, however, existing scholarship provides no satisfactory understanding of Congress’s power to control the other two branches through appropriations constraints.
This Article offers a systematic account of funding constraints as a separation-of-powers problem. Employing a methodology focused on text, structure, original intent, and the broad contours of historical practice, the Article argues that properly analyzing the problem requires disaggregating executive powers. Congress may not control some executive authorities, such as the veto, pardon, and appointment powers, through restricted or conditional appropriations. These powers are “resource-independent” because the president may exercise them personally, and because allowing Congress to control or materially influence their exercise would elide separation-of-powers distinctions essential to the constitutional structure. In contrast, certain other executive powers, most importantly war powers and law enforcement, are “resource-dependent”—they exist only insofar as Congress provides resources for their exercise. As to such powers, Congress properly holds near-plenary authority to restrict or condition use of available resources.
Hard cases arise in two areas: selective support of resource-independent powers and funding constraints on conduct of diplomacy. In these areas, an antimanipulation principle, modeled loosely on analogous federalism cases, provides the appropriate framework for balancing congressional and executive authority: conditions should be invalid only in narrow circumstances when the condition would unduly manipulate judgments that are properly the president’s alone.
Under this framework, the separation of powers shields presidents from congressional control with respect to powers that exist principally to provide a check on Congress. At the same time, the framework preserves a vital congressional check on the most normatively important executive powers—namely, those that involve bringing the government’s coercive and destructive capacities to bear through law enforcement and warfare.