Oversight refers to Congress's supervision of federal departments and agencies, as well as its review of presidential nominations and treaties by the Senate. This monitoring is carried out through standing committees and select committees as needed. Several factors theoretically contribute to making oversight more effective in the United States compared to parliamentary systems like the UK's. US party discipline is traditionally weak, and congressional careers are typically centered on the permanent standing committees rather than advancement to the executive branch. Despite some notable exceptions, such as the investigations into Watergate and Iran Contra (which occurred some time ago), oversight is not consistently conducted effectively. In recent years, increased partisan loyalties have often hindered oversight efforts. For instance, when both the presidency and Congress were controlled by the same party, as seen during the Republican control from 2002 to 2006, oversight activities decreased, leading to accusations of neglect. 

Following the Republicans' control of the House in 2011, the Oversight Committee, led by Darrell Issa, vigorously examined the administration on various matters like the 'Fast and Furious' operation and the IRS-Tea Party scandal. However, many viewed the committee as more focused on politically damaging the president rather than conducting impartial investigations. The motivation of Congress members also plays a role. Like all politicians, members of Congress are largely motivated by the desire for re-election, with oversight offering minimal benefits to themselves or their constituents and not significantly enhancing their re-election prospects. While some members, like Darrell Issa, may aim to establish themselves as enthusiastic pursuers of executive shortcomings, they are a minority.

Political factors often influence the effectiveness of Congress in conducting oversight. In times of divided government, the majority party in one or both houses of Congress often has a motivation to scrutinize their rivals in the executive branch. When the Democrats gained control of the House of Representatives in 2018, they initiated investigations into President Trump, ultimately leading to his first impeachment. Oversight tends to be weaker during periods of unified government, as the president's party typically dominates Congress. However, this dynamic is contingent on the president having control over their party. Despite having a majority in both houses of Congress at the beginning of his presidency, President Trump was unable to fulfill his promise of repealing Obamacare within his first 100 days. Presidents with high public approval ratings may encounter less resistance from Congress. The historically low public approval ratings of Congress can make it politically challenging for them to impede the actions of a popular president. For instance, following the 9/11 terrorist attacks, President George W. Bush's approval ratings soared to 90%, resulting in his administration facing minimal congressional scrutiny in the subsequent years.

Case Study  Trump's Taxes

Unlike all recent presidents Trump did not reveal his tax record when he was elected. After the Democrats gained control of the House of Representatives committees began oversight investigations in to Trumps finances and subpoenaed his tax records - Trump fought this in the courts. The Supreme Court decided that while in principle Congress had the right to subpoena the president's finances they had not refined their request narrowly enough and so returned the case to the lower courts (to be decided sometime in 2021) but they did decided that the President could be subpoenaed by the New York prosecutors instigating his possible obstruction of justice. The cases were Trump v Mazars (returned to lower courts) and Trump v Vance (New York)

In Congress, oversight comes in many forms including:

‘Necessary and Proper’

While the Constitution does not formally grant Congress the authority to oversee the actions of the executive branch, oversight is clearly implied in the many enumerated powers of Congress. The power of congressional oversight is reinforced by the “necessary and proper” clause (Article I, Section 8, Clause 18) of the Constitution, which grants Congress the power

“To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.”

The necessary and proper clause further implies that Congress has the power to investigate the actions of the executive branch. It would be impossible for Congress to apply its oversight powers without knowing whether federal programs are being administered properly and within their budgets and whether executive branch officials are obeying the law and complying with the legislative intent of the laws.

The U.S. Supreme Court has confirmed the investigative powers of Congress, subject to constitutional safeguards for civil liberties. In the 1927 case McGrain v. Daugherty, the court found that, in investigating actions taken by the Department of Justice, Congress had constitutionally considered a subject “on which legislation could be had or would be materially aided by the information which the investigation was calculated to elicit.”

Case study Hunter Biden

Increasing partisanship is undermining the validity of Congressional oversight.House Republicans continue to investigate the Biden family's finances, and they opened an impeachment inquiry into President Joe Biden in September as part of that effort.

They allege they have uncovered evidence of the president's knowledge of and role in his family members' domestic and foreign business dealings.

They have not yet shown President Biden committed an impeachable offence or provided any evidence of wrongdoing.

The panel escalated its probe on 8 November by sending subpoenas to Hunter Biden, as well as six of his relatives and two former associates.