On Wednesday, the US House of Representatives accused outgoing President Donald Trump of "inciting" violence in the Congress building, which will make him go down in history as the only US president to have twice been subjected to an impeachment mechanism that is rarely used in the first place.

The Constitution grants Congress the power to impeach the president, vice president, federal judges, or others in the event of treason, corruption, criminal offenses, or other major misdemeanors.

The mechanism takes place in two phases, with the parliament first voting by simple majority on the indictment, which details the facts attributed to the president.

And 232 deputies, including 10 Republicans, admitted, compared to 197, on Wednesday, the only charge against Trump, which is "incitement to rebellion."

After that, the trial enters the second phase in the Senate, which has a decision to try the accused president.

At the conclusion of deliberations, the 100 members of the Senate vote.

The president's conviction requires the approval of a two-thirds majority.

In this case, the president is dismissed automatically and without the possibility to appeal the decision, and his deputy takes over the presidency.

If not, the president is acquitted.

As for his conviction, a second vote by simple majority will be taken to prevent him from running again.

Previous cases

The United States witnessed 3 impeachment mechanisms for the president in its history, but all of them ended in acquittal.

The first impeachment mechanism took place in 1868 against Democratic President Andrew Johnson after he sacked one of his ministers.

In 1998, Democratic President Bill Clinton was charged with "perjury" over his relationship with White House intern Monica Lewinsky.

In December 2019, the House of Representatives charged Trump with "abuse of power, obstructing the work of Congress" after he asked Ukraine to investigate the son of his opponent (President-elect) Democrat Joe Biden, in exchange for granting military aid that has been frozen and is essential for the country experiencing war .

However, the Republican-controlled Senate acquitted him on February 5, 2020, after a two-week trial.

In 1974, Republican Richard Nixon preferred to resign to avoid his confirmed dismissal over the Watergate scandal.

Can a former president be tried?

Republican Senate President Mitch McConnell announced Wednesday that Trump's trial cannot take place before his term ends on January 20.

The constitution does not clarify the measures that can be taken after the duties of the accused president have ended.

In 1876, senators questioned whether it was within their powers to try Secretary of War William Belknapp after he left the administration, and concluded that this was possible, and the trial ended with his acquittal of the corruption charges against him.

The constitution does not specify a timetable.

Thus, the House of Representatives can wait before referring the indictment to the Senate, so that the new ruling team can be confirmed and Biden's first measures approved.

Trial scenarios

The Senate is divided equally between 50 Democrats and 50 Republicans.

Thus it seems difficult to achieve a two-thirds majority, especially since one Republican member voted with the Democrats in the first impeachment mechanism over the Ukrainian scandal.

But after Trump hinted that he might run in the 2024 elections, some Republicans from among the senators may endorse the charge against him in order to permanently exclude him from politics.

McConnell was informed that he did not rule out a vote to convict Trump, in a remarkable position, as he led with iron hand the previous trial in the Senate, keeping the majority members united behind the president.

Yet Trump remains hugely popular with millions of Americans, and some members may be reluctant to antagonize these voters.