The Mayorkas impeachment trial lasted just three hours on April 17, 2024, before the Senate voted 51-49 along party lines to dismiss the articles as unconstitutional—the shortest impeachment trial in modern history. The Senate's dismissal reflected a judgment that the articles charged policy failures, not the high crimes and misdemeanors the Constitution requires.
The Constitution sets four procedural rules for Senate impeachment trials. A two-thirds majority of senators present must vote to convict. Senators must take a special oath before the trial begins. Punishment cannot exceed removal from office and disqualification from holding future federal office. When the president is on trial, the Chief Justice presides rather than the vice president.
Everything else—the order of proceedings, whether witnesses testify, how long arguments run—the Senate establishes through unanimous consent or majority vote. House managers act as prosecutors. The Senate sits as a high court, evaluating evidence and ultimately voting on each article individually. This structure gives the Senate considerable control over its own process, which is why trials have ranged from the months-long Johnson proceedings in 1868 to the hours-long Mayorkas dismissal in 2024.