Over a course of weeks the Senate will hear evidence that the former president committed high crimes and misdemeanours while he was in office.
Democrats leading the case against the president however face an uphill struggle to convict the president, with support from a handful of Republicans required to seal a conviction.
What is impeachment?
Impeachment is a charge of misconduct brought against someone holding public office.
These charges are brought forward by members of congress and can be used to charge the United States president.
The American Constitution states that a president can be impeached and removed from office for a number of reasons, including "treason, bribery, or other high crimes and misdemeanours."
What high crimes and misdemeanours has Trump allegedly committed?
President Trump has been accused of sparking an insurrectionist attack on the US Capitol.
The president had urged his supporters to protest as Congress was counting the electoral votes that confirmed Biden's win.
Five people died, including a Capitol Police officer.
Impeachment articles charged Trump with "incitement of insurrection". The articles brought against Trump said that the president’s narrative "encouraged—and foreseeably resulted in—lawless action" and that he "threatened the integrity of the democratic system, interfered with the peaceful transition of power, and imperiled a coequal branch of Government,".
Will he be convicted of impeachment?
As things stand it seems unlikely.
For the former president to be convicted of impeachment a two-thirds majority are required to vote in favour of conviction. With the upper house of congress split 50-50 17 Republicans would be required to vote in favour of conviction, assuming all Democrats back conviction.
Republicans have already shown reluctance to turn on the former leader, with 45 senators backing a motion brought forward by Kentucky Senator Rand Paul which suggested the trial was unconstitutional. This reluctance will partly be down to a desire to keep the support of Trump’s base which remains strong despite his defeat. Those who backed Paul’s motion may have simply seen the appeal of not being required to publicly defend Trump’s actions.
Just one republican senator, Mitt Romney, voted to convict Trump at his first impeachment trial.
Republican senate leaders are split on the vote with Senate Minority Leader Mitch McConnell saying that he will keep an open mind ahead of the trial. John Barrasso of Wyoming, the third highest ranking Republican in the senate has said that "at this point, there's not going to be a conviction. You can read the writing on the wall.”