A U.S. president is impeached when the House of Representatives votes by a simple majority to approve one or more articles of impeachment. But what happens next? The process moves to the Senate for a trial. A two-thirds vote on at least one article is then required to convict and remove a president from office.
Andrew Johnson and Bill Clinton were impeached in 1868 and 1999 respectively, but were acquitted by the Senate and both served out the rest of their terms. Donald Trump was impeached by the House of Representatives in 2019 and acquitted by the Senate in 2020. Trump was impeached again on January 13, 2021.
So far, no president has been removed from office through impeachment. Richard Nixon arguably came the closest, but he resigned midway through the impeachment process.
The only way for Congress to remove a sitting president is to find him or her guilty during the Senate trial. In that trial, which comes after the House votes to approve articles of impeachment, the Chief Justice of the United States presides and the 100 members of the Senate serve as the jury. A full two-thirds of the Senate jurors present needs to vote “guilty” for a president to be convicted.
Article I, Section 3 of the Constitution gives the Senate “sole power to try all impeachments” and sets forth three requirements that underscore the seriousness of an impeachment trial: 1) senators are put under oath; 2) the Chief Justice presides, not the vice president; and 3) a two-thirds “supermajority” is required to convict.