Only two presidents other than Donald Trump have been impeached, and in the case of Bill Clinton in 1998 and Andrew Jackson in 1868, the process took many weeks, if not months.
The current efforts by Democrats in the House of Representatives to impeach the U.S. president, by contrast, are expected to last just days. Indeed, they have to - Trump is due to leave the White House to make way for President-elect Joe Biden next Wednesday on January 20.
The reason the impeachment process - including that of Trump's original impeachment in December 2019 - takes so long is that it involves hearings, investigations, and then finally a debate and vote.
This time, the House will skip the formalities of hearings and investigations and move straight to a debate, which is expected to begin on Wednesday.
Time isn't the only consideration for the sped-up process this time around: unlike the Ukraine scandal that led to Trump's impeachment in 2019, there is no need for the submission of evidence.
The very members of the House who will vote this week were witnesses to what happened a week ago today when thousands of Trump supporters occupied the Capitol building in Washington.
Earlier, Trump had told his supporters to protest the counting of electoral college votes that would confirm the election of Joe Biden. He urged them to "fight back" and "show strength".
As such, the debate, on Wednesday, will be on a single impeachment charge: “incitement of insurrection."
“President Trump gravely endangered the security of the United States and its institutions of Government,” reads the four-page impeachment article, which was introduced by Democratic Reps. David Cicilline of Rhode Island, Ted Lieu of California, and Jamie Raskin of Maryland.
“He will remain a threat to national security, democracy, and the Constitution if allowed to remain in office,” it reads.
What happens after the vote?
Once the House passes the articles, Pelosi can decide when she sends them to the Senate.
Under the current schedule, the Senate is not set to resume full sessions until January 19, which is the day before Biden's inauguration.
Some Democrats suggested Pelosi might wait to send the articles and allow Biden to begin his term without impeachment hanging over him. But many other Democrats have urged Pelosi to move immediately.
Senate Democratic leader Chuck Schumer, who will be in charge once Biden is sworn in, suggested in a letter to colleagues Tuesday the chamber might divide its time between confirming Biden's nominees, approving COVID relief and conducting the trial.
If the trial isn't held until Trump is already out of office, it could still have the effect of preventing him from running for president again.
Biden has said it’s important to ensure that the “folks who engaged in sedition and threatening the lives, defacing public property, caused great damage — that they be held accountable.”
It's unlikely, for now, that enough Republicans would vote to convict, since two-thirds of the Senate is needed. Yet some Republicans have told Trump to resign, including Pennsylvania Sen. Pat Toomey and Alaska Sen. Lisa Murkowski, and few are defending him.
Later, visiting the US-Mexico border wall in Texas for his first trip since the assault on Capitol Hill, he resorted to type, ranting at his opponents over immigration.
Trump called for respect for law and order, but otherwise made only scant reference to last week's attack — in his name — on the seat of US democracy. He highlighted border security in an attempt to promote his legacy but said not a word on the lapse of security in Washington or the police officer and others who died.
What are Republicans saying?
Republican Sen. Ben Sasse 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 Sen. Lindsey Graham, long a key ally of the president, has been critical of his behavior in inciting the riots but said impeachment “will do far more harm than good.”
Only one Republican voted to convict Trump last year — Utah Sen. Mitt Romney.
What does it mean?
Democrats say they have to move forward, even if the Senate doesn't convict.
Vermont Senator Bernie Sanders tweeted on Friday that some people might ask why they would try to impeach a president with only a few days left in office.
“The answer: Precedent,” he said. “It must be made clear that no president, now or in the future, can lead an insurrection against the U.S. government.”