1.Constitutional Authority for Congressional Oversight and Impeachment
Article I of the Constitution vests in the House of Representatives the "sole Power of Impeachment." Congress is authorized to conduct oversight and investigations in support of its Article I powers. The Supreme Court—and previous Presidents—have acknowledged these authorities.
Overview
The House's Constitutional and legal authority to conduct an impeachment inquiry is clear, as is the duty of the President to cooperate with the House's exercise of this authority. The Constitution vests in the House of Representatives the "sole Power of Impeachment" as well as robust oversight powers. As the Founders intended, the courts have agreed, and prior Presidents have acknowledged, the House's sweeping powers to investigate are at their peak during an impeachment inquiry of a President. Congress has also enacted statutes to support its power to investigate and oversee the Executive Branch.
Unlike President Donald J. Trump, past Presidents who were the subject of impeachment inquiries acknowledged Congress' authority to investigate and—to varying degrees—complied with information requests and subpoenas. Even so, the House has previously determined that partial noncooperation can serve as a ground for an article of impeachment against a President as it would upend the separation of powers to allow the President to dictate the scope of an impeachment inquiry. When President Richard Nixon withheld tape recordings and produced heavily edited and inaccurate records, the House Judiciary Committee approved an article of impeachment for obstruction.
Constitutional Power of Congress to Investigate—and to Impeach
Article I of the U.S. Constitution gives the House of Representatives the "sole Power of Impeachment."1 The Framers intended the impeachment power to be an essential check on a President who might engage in corruption or abuse power. For example, during the Constitutional Convention, George Mason stated:
No point is of more importance than that the right of impeachment should be continued. Shall any man be above Justice? Above all shall that man be above it, who can commit the most extensive injustice? ... Shall the man who has practised corruption & by that means procured his appointment in the first instance, be suffered to escape punishment, by repeating his guilt?2
Congress is empowered to conduct oversight and investigations to carry out its authorities under Article I.3 In light of the core nature of the impeachment power to the nation's Constitutional system of checks and balances, Congress' investigative authority is at its zenith during an impeachment inquiry.4
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