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.

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Impeachment Trial Operates Like a Criminal Trial

Impeachment of President Andrew Johnson
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The impeachment trial of President Andrew Johnson in the Senate on March 13, 1868. 

The Senate impeachment trial operates much like a criminal trial. The prosecution in an impeachment trial is represented by “impeachment managers” from the House of Representatives who get the first chance to present their evidence to the Senate.

According to Senate rules first established for Johnson’s 1868 impeachment trial, everyone in the Senate chamber is required to keep absolute silence, “on pain of imprisonment,” as the House managers make their case against the president.

The president’s defense team then presents its opening arguments followed by the calling of witnesses. Both sides can call witnesses and cross-examine the opposing party’s witnesses. Senators can be called as witnesses, too, and actually testify standing at their desk in the chamber.

Senators Act as Jurors

Can the president be called as a witness in his or her own impeachment trial? Yes, either side can call the president as a witness in the Senate trial, but the president does not have to appear. According to Senate rules, if the president refuses to testify, the “trial shall proceed, nevertheless, as upon a plea of not guilty.” Neither Johnson nor Clinton appeared at their impeachment trials.

As jurors, senators sit quietly and observe the proceedings, but they are allowed to submit written questions to both the prosecution and defense, and also to witnesses. When both sides have finished presenting their arguments, the Senate adjourns behind closed doors to deliberate.

The length of the impeachment trial depends on how many witnesses are called, how many articles of impeachment are being considered, and how long it takes the Senate to deliberate. 

The impeachment trial of Andrew Johnson took nearly three months, while Bill Clinton’s impeachment trial lasted a little more than a month. Trump's first impeachment Senate trial was decided in just under three weeks.

Offenses That Qualify as Impeachable 

What offenses are deemed “impeachable”? Article II, Section 4 of the Constitution states that a president can be removed from office if convicted of “treason, bribery, or other high crimes and misdemeanors.” But that doesn’t mean that a president needs to be found guilty of a crime to be impeached. Congress has established that a president can also be removed for abuses of power, misusing the office for personal gain, and “behavior incompatible with the function and purpose of the office.”

When it’s time to deliver their verdict, each senator stands at his or her desk and simply states “guilty” or “not guilty” to each article of impeachment. If the prosecution fails to get two-thirds of the Senate (67 senators) to vote guilty on any of the charges, the president is acquitted and keeps his or her job.

Close Verdict on Johnson's Trial, Not Clinton's

Senate Trial for the Impeachment of President Andrew Johnson
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The vote of the Senate during the impeachment of President Andrew Johnson.

In the 1868 Johnson impeachment trial, the embattled president was just one vote away from being removed from office on each of the three charges put to a vote. There were 11 total articles of impeachment, but the Senate voted to adjourn the trial when it was clear that the voting would be the same for each remaining charge.

In the 1999 Clinton impeachment trial there were two articles of impeachment, and the Republican-led prosecution only won 45 guilty votes for the perjury charge and 50 for the obstruction of justice charge with a number of Republican “defectors” voting to acquit on both counts.

In February 2020, the U.S. Senate voted to acquit President Trump of charges that he abused his power and obstructed Congress. The tally for conviction fell far below the 67-vote threshold necessary for removal and neither article of impeachment drew a simple majority. The House of Representatives voted to impeach President Trump again on January 13, 2021, making him the only president in history to be impeached twice. The 2021 impeachment article accused Trump of “incitement of insurrection.” The charge was sent to the Senate to be adjudicated, where he was again found not guilty. 

If Convicted, Decision on Punishment Is Next

If a president is acquitted in the Senate, the impeachment trial is over. But if he or she is found guilty, the Senate trial moves to the sentencing or “punishment” phase. The Constitution allows for two types of punishments for a president found guilty of an impeachable offense: “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.”

The first punishment, removal from office, is automatically enforced following a two-thirds guilty vote. But the second punishment, disqualification from holding any future government position, requires a separate Senate vote. In this case, only a simple majority is required to ban the impeached president from any future government office for life. That second vote has never been held since no president has been found guilty in the Senate trial.

Senate Can Change All the Rules

The proceedings and customs of the Senate impeachment trial can be changed at any time. The Senate, with its “sole power” to try impeachments, can vote by a simple majority to change almost all of the rules. In fact, if it wanted to, the Senate could refuse to vote on articles of impeachment entirely and simply dismiss the case. In the two previous presidential impeachments, however, that has never happened.

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