Congressional Oversight after Trump v. United States
The Supreme Court’s 2024 decision in Trump v. United States has been widely recognized as a “dramatic, radical expansion” of presidential power. But one implication of that expansion, which has thus far received little attention, is how in bolstering the “conclusive and preclusive” nature of core executive powers, the decision shrunk the “legislative” space where Congress can conduct oversight. In other words, Trump v. United States diminished not only Congress’s power to legislate with respect to the executive branch but also Congress’s power to investigate it.
The full ramifications of Trump are not yet known. But, should Democrats retake one or both houses of Congress in the 2026 midterms, the executive branch will almost certainly wield the Trump decision aggressively to resist congressional investigations. Congressional Democrats will undoubtedly reject these broad readings of Trump. But congressional Democrats will also likely make creative arguments to circumvent the decision’s strictures, including potentially by invoking Congress’s power to investigate pursuant to its power to propose constitutional amendments.
Congress has investigated the executive branch since the nation’s earliest days, beginning in 1792 when the House of Representatives established a special committee to probe the defeat of U.S. troops under the command of Gen. Arthur St. Clair.
But the Constitution does not grant Congress a freestanding investigative power. Rather, the Supreme Court has long understood Congress’s power of inquiry to be auxiliary to Congress’s legislative function. As the Court explained in Trump v. Mazars, when quoting from established precedent, Congress’s oversight power “is justified solely as an adjunct to the legislative process.” Congressional oversight must therefore “concern a subject on which legislation ‘could be had.’”
The executive branch has taken the view that this limitation walls off certain core executive branch functions—such as the president’s pardon and removal powers—from congressional oversight. The executive branch invoked this argument when resisting congressional inquiries into President Clinton’s grant of clemency to Puerto Rican militants and President George W. Bush’s dismissal and replacement of U.S. attorneys.
The executive branch, however, still coupled its arguments about the illegitimacy of the probes with formal assertions of executive privilege. Under this belt-and-suspenders approach, the executive branch essentially argued that Congress’s request was likely illegitimate because it strayed outside Congress’s legislative authority, but that even assuming Congress had oversight authority, the information was protected by executive privilege because the executive branch’s confidentiality interests outweighed any congressional need.
The Supreme Court’s 2024 Trump decision powerfully bolsters the executive branch’s contention that certain core executive functions are off limits from congressional oversight. Much of the attention has understandably focused on the results of that case—an effectively fatal blow to Special Counsel Jack Smith’s efforts to prosecute President Trump on charges related to election interference. But the decision’s broader reasoning will have important repercussions for future congressional oversight.
In assessing the extent to which the president is shielded from federal criminal law, the Supreme Court noted in Trump that “Congress cannot act on, and courts cannot examine, the President’s actions on subjects within his ‘conclusive and preclusive’ constitutional authority.” In other words, within these domains, the president’s conduct cannot be prosecuted under the law because Congress lacks the power to pass laws that would make the president prosecutable. In an echo of the executive branch’s position, the Court listed, among other things, the president’s pardon and removal powers as areas within the president’s exclusive constitutional authority. The Court also stated that “the Executive Branch has ‘exclusive authority and absolute discretion’ to decide which crimes to investigate and prosecute” and, relatedly, that the president has “exclusive authority over the investigative and prosecutorial functions of the Justice Department and its officials.”
Again, these statements were made in the context of describing areas of exclusive executive authority in which Congress could not legislate (including to criminalize presidential conduct). The Court did not directly address Congress’s investigative authority. But because it has long been established that Congress “cannot inquire into matters which are within the exclusive province of one of the other branches of the Government,” the executive branch will doubtless invoke Trump to resist congressional oversight. And some of the opinion’s language—such as the executive branch having “exclusive authority over the investigative and prosecutorial functions of the Justice Department”—can be construed quite capaciously.
Of course, to Trump’s critics, some of his actions in these “exclusive” domains are among the most troubling of his second term in office. His detractors have, for example, criticized the alleged targeting of Trump’s political foes for criminal prosecution, as well as his pardons. Democrats have made clear that, should they retake control of one or both chambers of Congress, investigations into both areas will be among their highest oversight priorities. The executive branch will almost certainly rely on Trump as a powerful tool to oppose Congress’s demands.
Congress will push back. As an initial matter, Congress is likely to contest an expansive reading of Trump that puts broad swaths of executive branch activity outside the reach of Congress’s legislative oversight. Congress may also get creative in its investigative rationales, attempting to justify informational requests touching on the exercise of core executive authority by saying such information is needed to inform legislation that sits outside such core executive areas. For instance, expect Congress to contend that it requires information about presidential clemency decisions not because Congress is seeking to regulate the president’s own exercise of the pardon power but because it is attempting to regulate the conduct of pardon applicants or recipients.
And Congress may invoke other authorities in support of its investigations. While Trump cabined Congress’s authority to legislate (and so investigate pursuant to that legislative authority), Congress has other authorities beyond its legislative power. Congress may well explore using these other authorities to investigate exercises of core executive powers.
For example, Congress could investigate using its impeachment powers. Jonathan Shaub proposes this path in one of the few treatments to date of the oversight implications of Trump (another text that addresses these implications is the most recent edition of When Congress Comes Calling, a congressional oversight handbook that Jenner & Block and the Project on Government Oversight updated in 2025). The power to impeach encompasses a corresponding power to investigate. And, because impeachments target “treason, bribery, or other high crimes and misdemeanors,” investigations conducted pursuant to the impeachment power are widely understood to have greater reach than investigations conducted as part of ordinary legislative oversight. President Polk once said that the House, in exercising its impeachment power, could “penetrate into the most secret recesses of the executive departments.”
At the same time, the impeachment power has significant limitations. It resides solely with the House—the Senate cannot invoke it. And it reflects a grave step that can be both politically costly and polarizing. In today’s climate, any investigation that proceeds under the banner of impeachment would likely lose any hope of broad bipartisan support, even on subjects where there might otherwise be shared interest in reform.
As an alternative, Congress may well justify contested investigations by asserting that the investigations are an exercise of Congress’s power to propose constitutional amendments.
Article V of the Constitution provides that “Congress, whenever two thirds of both houses shall deem it necessary, shall propose amendments to this Constitution.” Congress may argue that the same logic that permits Congress to investigate pursuant to its legislative function—namely, that “without information, Congress would be shooting in the dark, unable to legislate ‘wisely or effectively’”—likewise supports Congress’s ability to investigate pursuant to this amendment power. Without the ability to inform itself, how would Congress be able to “deem it necessary” to propose an amendment?
And, Congress would likely say, because a constitutional amendment can alter the Constitution’s existing delegation of powers across the branches, Congress should be able to inquire into areas of authority that, at present, are allocated exclusively to the other branches. Congress might well argue, for example, that in considering whether to propose an amendment to the president’s pardon power, it is important to understand how presidents have actually exercised it.
This would not be the first time that Congress conducted fact finding as it considered constitutional amendments. The Senate Committee on the Judiciary, for instance, has held hearings to consider constitutional amendments that would permit more stringent campaign finance laws. (Among the witnesses at a 2014 hearing on the subject was then-Professor Jamie Raskin, now the ranking member of the House Judiciary Committee, the House Committee responsible for constitutional amendments.) As another, earlier, example, Congress held hearings on the Equal Rights Amendment before sending it to the states for ratification. And in the wake of the Civil War, the Joint Committee on Reconstruction “conducted hearings and grappled with the constitutional questions that followed emancipation.” The Joint Committee, “authorized to send for persons and papers,” heard testimony from 144 witnesses and introduced, among other things, what ultimately became the 14th Amendment. So there is arguably precedent that Congress could invoke for a distinct power of inquiry pursuant to Article V.
The executive branch would likely object, of course. One potential objection is that this “constitutional oversight” power could be used simply as an end run around the current restrictions on Congress’s legislative oversight. That there are certain areas, entrusted to the other branches, that Congress cannot investigate pursuant to its legislative powers reflects the separation of powers enshrined in the Constitution. Congress, the argument would go, should not be able to circumvent the Constitution’s existing structure—and thereby invade the separation of powers—by invoking the mere possibility of changing that structure. In turn, Congress might reply that, because an amendment can, by definition, alter the scope of Article II, the executive cannot use Article II as a shield to block Congress’s inquiry into whether it should be amended.
Additionally, even on subjects where Congress may unquestionably request information from the executive branch, the executive branch may still claim that its confidentiality interests in the requested information outweigh Congress’s need for that information. So the branches would likely also argue over the standard an Article V informational demand must meet to overcome such confidentiality claims. It is commonly understood, for instance, that Congress’s informational needs are considered less weighty in the context of legislation than impeachment, not least because, to borrow from an influential en banc opinion from the U.S. Court of Appeals for the District of Columbia Circuit, “legislative judgments normally depend more on the predicted consequences of proposed legislative actions and their political acceptability, than on precise reconstruction of past events.”
Perhaps, under this same logic, Article V informational demands would be accorded equal or even lesser weight than legislative demands—the latter of which might mitigate concerns that such demands are purely an end run around the limits on Congress’s legislative oversight authority. One could imagine a sliding scale where investigative demands pursuant to the impeachment power would be the narrowest in scope but the most penetrating in reach; demands pursuant to the amendment power would be broadest in scope but least powerful in the face of executive objections; and demands pursuant to legislative oversight would be somewhere in the middle.
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Among its many ramifications, Trump has quietly weakened Congress’s ability to conduct legislative oversight over the executive branch. As a result, a Congress hostile to the executive branch will likely look for alternative paths to pursue its investigative priorities. Congress’s authority to investigate pursuant to its Article V power to propose amendments has been undertheorized, perhaps because, under a more capacious understanding of Congress’s authority to conduct legislative oversight, there has been little need to explore alternatives. But now, if Democrats control one or both houses in the next Congress, the coming years may see Congress invoke its Article V authority in order to investigate areas of the executive branch that might otherwise be off limits.
