The U.S. Constitution provides for impeachment and removal of the President as an extreme, and rarely implemented, check on the executive branch.
Article II, § 4 of the Constitution provides that, “[t]he President, Vice President and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.” Pursuant to Article I, § 2, provides that the House of Representatives has the “sole Power of Impeachment.”
After there is an Impeachment by the House, the Senate has the sole authority to try the Impeachment. Specially, Article I, § 3, of the U.S. Constitution provides that:
The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present.
Finally, an impeachment and removal from office is not equivalent to a guilty verdict by a court and cannot result in imprisonment without proper court procedures (e.g., jury trial). Article I, § 3, provides that:
Judgment in Cases of impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States: but the Party convicted shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.