The U.S. Constitution permits Congress to remove a president before his or her term is up if enough senators vote to say that they committed “treason, bribery, or other high crimes and misdemeanours.” Article Two, Section 4 of the Constitution gives the House of Representatives the sole power to impeach a federal official, including the president. On October 31 the House voted to approve and proceed with its impeachment inquiry. The resolution, passed on a mostly party-line 232-196 vote, sends a clear signal that a vote to impeach President Donald Trump, and a trial in the Senate, is all but inevitable.
A two-thirds majority in the Senate is required to convict and remove a president from office -- which has never successfully happened. While the Constitution sets out that if the House impeaches an official, the next step is for the Senate to hold a trial, there is no precise enforcement mechanism.
Article One of the Constitution stipulates that the Chief Justice of Supreme Court -- currently John Roberts -- should preside over any Senate trial.
Trump becomes just the fourth president to be subject to a formal impeachment effort.