United States President Donald Trump has been impeached by the House days before leaving office, becoming the first American president to be impeached twice.

The previous three impeachments — those of Presidents Andrew Johnson, Bill Clinton and Trump — took months before a final vote, including investigations in the House and hearings. This time it only took a week after Trump encouraged a crowd of his supporters who attacked the US Capitol.

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Democrats and 10 Republicans voted to impeach Trump on one charge: incitement of insurrection.

Outgoing Senate Majority Leader Mitch McConnell has said the Senate will not begin a trial until next Tuesday, at the very earliest, which is the day before Democrat Joe Biden is sworn in as president. It’s unclear, for now, exactly how that trial will proceed and if any Senate Republicans will vote to convict Trump.

Even though the trial won’t happen until Trump is already out of office, it could still have the effect of preventing him from running for president again.

A look at the next steps:

Sending to the Senate

Once the House votes to impeach, the speaker of the House can send the article or articles over to the Senate immediately — or she can wait a while. Speaker Nancy Pelosi hasn’t yet said when she will send them, but many Democrats in her caucus have urged her to do so immediately.

Pelosi has already appointed nine impeachment managers to argue the case against Trump in a Senate trial, a sign that she will send them sooner rather than later.

Once the articles are sent over — that is usually done with an official walk from the House to the Senate — then the majority leader of the Senate must start the process of having a trial.

The Senate schedule

The Senate is not scheduled to be in session until Jan 19, which could be McConnell’s last day as Senate leader. Once Vice President Kamala Harris is sworn in, making her the president of the Senate, and Georgia’s two Democratic senators are also sworn in, Senate Democratic leader Chuck Schumer will take charge and determine how the trial will proceed.

McConnell said he will not bring the Senate back on an emergency basis to start the trial, so the earliest it could begin would be on Tuesday. That means the trial is certain to take place after Trump has already left office.

McConnell noted that the three previous Senate trials lasted “83 days, 37 days, and 21 days respectively”.

All eyes on McConnell

McConnell believes that Trump committed impeachable offenses and considers the Democrats’ impeachment drive an opportunity to reduce the divisive, chaotic president’s hold on the GOP, a Republican strategist told The Associated Press on Wednesday.

And McConnell told major donors over the weekend that he was through with Trump, said the strategist, who spoke on condition of anonymity to describe McConnell’s conversations. His wife, former Transportation Secretary Elaine Chao, resigned from Trump’s Cabinet soon after the riots.

But despite sending signals, McConnell has been characteristically quiet in public. In a note to colleagues Wednesday released by his office, McConnell said he had “not made a final decision on how I will vote”.

Senate politics

If McConnell voted to convict, other Republicans would surely follow. But no GOP senators have said how they will vote, and two-thirds of the Senate is needed.

Still, some Republicans have told Trump to resign, including Pennsylvania Senator Pat Toomey and Alaska Senator Lisa Murkowski, and few are defending him.

Republican Senator Ben Sasse of Nebraska has said he would take a look at what the House approves but stopped short of committing to support it.

Other Republicans have said that impeachment would be divisive. South Carolina Senator Lindsey Graham, long a key ally of the president, has been critical of his behaviour in inciting the riots but said impeachment “will do far more harm than good”.

Utah Senator Mitt Romney was the only Republican to vote to convict Trump in last year’s impeachment trial, after the House impeached Trump over his dealings with the president of Ukraine.

In the House, 10 Republicans joined Democrats in voting to impeach Trump, including Wyoming Representative Liz Cheney, the third-ranking Republican. Every single House Republican voted against Trump’s first impeachment in 2019.

Trump's future

If the Senate were to convict, lawmakers could then take a separate vote on whether to disqualify Trump from holding future office.

Schumer said on Wednesday: “Make no mistake, there will be an impeachment trial in the United States Senate; there will be a vote on convicting the president for high crimes and misdemeanours; and if the president is convicted, there will be a vote on barring him from running again.”

In the case of federal judges who were impeached and removed from office, the Senate has taken a second vote after conviction to determine whether to bar the person from ever holding federal office again.

Only a majority of senators would be needed to ban him from future office, unlike the two-thirds needed to convict.

Different charges, different impeachment

This impeachment trial is likely to differ from the last one in many ways.

The House charges in 2019 on Trump’s dealings with the president of Ukraine, whom he urged to investigate Biden, came after a lengthy investigation and testimony from multiple government officials. While Democrats unanimously criticised the conduct and charged Trump with abuse of power, the charges wove together a complicated web of evidence.

This time, Democrats felt there was little need for an investigation — the invasion of the Capitol played out on live television, and most members of Congress were in the building as it happened.

Trump’s speech beforehand, in which he told his supporters to “fight like hell” against the election results, was also televised as Congress prepared to officially count the votes.

House Intelligence Committee Chair Adam Schiff, who led the last House impeachment team, said the insurrection at the Capitol was an “impeachable offence committed in broad daylight, in which the whole country was a witness”.

He said the lightning-fast impeachment “was required by the exigency of the circumstances, and also made possible by the very nature of the crime”.

Trump's defence

Trump is likely to argue at trial that his remarks were free speech protected by the US constitution’s First Amendment and that, while he told supporters to “fight”, he did not intend it as a literal call to violence.

Trump released a videotaped statement on Wednesday, shortly after the impeachment vote, saying he condemned last week’s violence.

“Violence and vandalism have absolutely no place in our country and no place in our movement,” Trump said.

Challenging disqualification

Brian Kalt, a law professor at Michigan State University, said it was certainly possible that Trump could challenge a disqualification in court.

A Supreme Court case from 1993 makes clear that the court is wary of second-guessing how the Senate handles impeachment. In that case, involving an accused judge, the court said whether the Senate had properly tried an impeachment was a political question and could not be litigated.

If Trump is disqualified, the current Supreme Court might want to clarify whether the move was lawful, Kalt said.

Trump appointed three of the Supreme Court’s nine members: Justices Neil Gorsuch, Brett Kavanaugh and most recently Amy Coney Barrett. The court now has a six-judge conservative majority.

“If you are going to say someone can’t run, you want to get that litigated and settled sooner rather than later,” Kalt said.

Impeachment article

The four-page article of impeachment says that Trump “gravely endangered the security of the United States and its institutions of Government”.

It was introduced by Democratic Reps David Cicilline of Rhode Island, Ted Lieu of California and Jamie Raskin of Maryland, all of whom have been tapped to serve as impeachment managers in the Senate trial.

The article says Trump’s behaviour is consistent with his prior efforts to “subvert and obstruct” the results of the election and references his recent call with the Georgia secretary of state, in which he said he wanted him to find him more votes after losing the state to Biden.

Trump has falsely claimed there was widespread fraud in the election, and the baseless claims have been repeatedly echoed by congressional Republicans and the insurgents who descended on the Capitol.

As the protesters broke in, both chambers were debating GOP challenges to the electoral vote count in Arizona as part of the process for certifying Biden’s election win.