The first investigation
While none at the 1791 Battle of Wabash knew it, what was then “the most decisive defeat in the history of the American military” would serve as the foundation of modern congressional oversight authority.
The investigation, which focused on the conduct of American General Arthur St. Clair and the events that led to the deaths of 650 American soldiers, was unlike anything Congress had undertaken before, in part because it was not entirely clear that Congress could attempt it at all. The central question was not just what went wrong at Wabash, but whether Congress had the authority to investigate the president and his cabinet in the first place. The final report cleared General St. Clair of any wrongdoing, but the investigation itself settled something more lasting: that Congress had the power to scrutinize the executive branch.
Today, the public’s image of congressional oversight is strongly influenced by more attention-grabbing inquiries: the Army–McCarthy hearings, Watergate, Iran-Contra, and the impeachments of Donald Trump. That said, not all congressional oversight captures so much public attention, nor does it always produce positive outcomes for the American people.
As the Project on Government Oversight, an independent government watchdog, put it, “Congressional investigations should be designed to serve the American people, to find the facts that can help shape reforms. More and more, however, it seems as if they’re designed to serve members of Congress, to find the sound bites that will produce attention.” The 2023 resolution establishing the House Select Subcommittee on the Weaponization of the Federal Government, for instance, authorized the panel to investigate any part of the executive branch with no intended legislative output besides a “final report.”
As investigations are increasingly used as purely partisan tools, the more unclear the connection between oversight and identifiable legislative purpose has become. It’s a problem that has cost Congress in the courts and in its capacity to make government actually work.
From deference to scrutiny
The investigative powers available to Congress are “a product of Supreme Court case law,” making it essential to understand a few of the cases that have had an outsized impact on oversight authority. To start at the most expansive point of that authority, the Constitution Annotated, which serves as the government’s official record of constitutional interpretation, marks McGrain v. Daugherty as the “high-water mark” of congressional oversight power. In that 1927 case, the Court upheld the conviction of Mally Daugherty, the brother of Attorney General Harry Daugherty, for refusing to comply with a subpoena to testify before a Senate committee on issues related to the Teapot Dome scandal. As a result, the Senate had Daugherty detained for contempt. In rejecting his appeal, the Supreme Court decided there is a “presumption” that congressional investigations aid legislative ability and held that the legislature had the power to hold those who do not comply in contempt.
In subsequent cases, courts have recognized that the McGrain presumption is rebuttable. In 1954, the House Un-American Activities Committee cited labor leader John Watkins for contempt after he refused to answer whether his acquaintances had been associated with the Communist Party. On appeal in 1957, the Court held that Watkins’s refusal had been legal and that Congress had no right to expose private activities without a clear legislative aim.
More recently, in Trump v. Mazars (2020), the Court declined to extend the McGrain presumption to congressional subpoenas issued to the accounting firm Mazars (now Forvis Mazars) seeking financial records related to Donald Trump and his businesses. Instead, the Court set forth four factors, characterized as nonexhaustive, that courts must consider to assess the legitimacy of congressional subpoenas that invoke separation of powers concerns. Specifically, courts must consider whether the legislative purpose is adequate, the subpoena sufficiently narrow, the factual basis sufficient, and the burden on the executive acceptable.
Though limited to the presidential context, analysts have warned that “the Mazars case shows that if congressional oversight investigations wind up in court, the process can undermine them even when the law is on Congress’s side.” The legal precedent governing congressional oversight is far more complicated than just these three cases, but the Court’s increased willingness to depart from the broader deferential baseline that has otherwise governed congressional investigations at a minimum complicates the oversight powers picture for Congress going forward.
Oversight in service of state capacity
The Niskanen Center’s State Capacity team asserts that government must consistently adapt and improve by learning from real-world outcomes. Congressional oversight is fundamental to this feedback loop. Oversight investigations can help ensure that programs Congress enacts, from overseas aid to law enforcement efforts, are producing the impact and outcomes that lawmakers intend. In that sense, just as it is Congress’s responsibility to write laws with effective implementation in mind, Congress can also conduct oversight with effective implementation in mind. The Trump administration’s Department of Government Efficiency, while ineffective in rooting out federal inefficiency, was created because of significant public mistrust about how government programs are run. Congress can, and should, be at the forefront of improving the system of feedback loops necessary to restore government capacity and, with it, public trust in government.
At a base level, Congress must be more explicit about the legislative objectives animating an investigation. Oversight should clarify how programs are functioning in practice, identify deficiencies in statutory authority, and recommend reforms to improve outcomes. The gradual narrowing of judicial deference to congressional oversight prerogatives over the past several decades suggests that institutional credibility matters. Courts are more willing to shield oversight targets when legislative purpose is unclear or investigative tools are unrelated to legislative goals. It’s on Congress’s shoulders to make the links between oversight and legislative purpose clear, cogent, and able to withstand judicial scrutiny.
What should the future of congressional oversight look like? One good model is the bipartisan coalition of Senators Chuck Grassley (R-IA), Ron Wyden (D-OR), Todd Young (R-IN), and Ben Cardin (D-MD), who in 2020 investigated the government’s Organ Procurement and Transplantation Network (OPTN) program, which a single federal contractor, United Network for Organ Sharing (UNOS), had managed for 40 years. From numerous hearings and reports, the group of senators determined that UNOS’s management had led to significant failures, including the discarding of organs that were viable for transplants.
The group’s final report noted that experts estimated its recommendations to improve OPTN — chiefly, opening OPTN to more contractor competition — would allow 28,000 more transplants each year and save up to $40 billion over the next decade. The senators championed the Securing the U.S. Organ Procurement and Transplantation Network Act (H.R.2544), which incorporated many of their recommendations when President Joseph R. Biden signed it into law in 2023.
If state capacity depends on feedback, learning, and course correction, then rigorous, thoughtful oversight competently conducted is central to the enterprise. The converse is no less true: oversight conducted carelessly and with insufficient legislative purpose imperils the very authority necessary to do so. The future of effective governance rests not only on what Congress chooses to do, but on how it does it.
