Trump: How could he be impeached?
Speculation that Donald Trump may be impeached has been rekindled by fresh accusations that he paid hush money to women with whom he allegedly had affairs.
Coming on top of the Russia inquiry, the allegations emerging from the trial of his former lawyer, Michael Cohen, could probably merit pursuing in the criminal justice system were Mr Trump not the sitting president.
As legal scholars suggest that he cannot be prosecuted during his presidency, the only way he could be removed from office would be by impeachment.
But just how does that happen? And exactly who has been impeached in the past? The answer may surprise you...
What is impeachment anyway?
In this context, to "impeach" means to bring charges in Congress which will form the basis for a trial.
The US constitution states a president "shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high crimes or misdemeanours".
The process of impeachment has to be started by the House of Representatives and only needs a simple majority to pass. The trial will be held in the Senate.
But here, a two-thirds vote is necessary for removal - and this milestone has never been reached in America's history.
Who has actually been impeached?
Despite it being threatened on numerous occasions, only two presidents have ever actually been impeached.
Most recently, Bill Clinton - the 42nd president of the United States - found himself impeached on the grounds of perjury in front of a grand jury and obstruction of justice, after he lied about the nature of his affair with Monica Lewinsky and then allegedly asked her to lie about it as well.
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The House voted 228 to 206 in favour of impeaching President Clinton for the first charge, and 221 to 212 on the second.
It should be noted that, at the time in December 1998, Mr Clinton's approval rating as president was at 72%.
However, when it reached the Senate in 1999, it failed to get close to the two-thirds backing it needed in order to pass. As an analysis piece the BBC ran at the time noted, "in their eagerness to bring down the president, they never stopped to think whether the charges could be proved beyond reasonable doubt".
The second? Clue: It wasn't Richard Nixon. (More on this lower down).
In fact, the only other president impeached was Andrew Johnson, who served for four years from 1865 - the 17th person to hold the role.
He was impeached by the House in 1868. The vote came just 11 days after he got rid of Edwin Stanton, his secretary of war - a man who didn't agree with his policies.
The parallels between Mr Stanton's firing and that of FBI director James Comey - a man who also reportedly disagreed with Mr Trump - did not go unnoticed in the American press.
Unlike Mr Clinton, however, Mr Johnson's survival was a close call: the two-thirds majority was missed by just one vote, thanks to a number of Republicans.
Later, Iowa senator James Grimes explained: "I cannot agree to destroy the harmonious working of the Constitution for the sake of getting rid of an unacceptable president."
So - could Mr Trump be impeached?
In theory yes. He could technically be accused of violations of his oath of office to "preserve, protect, and defend" the US constitution, according to the writers of Lawfare Blog.
In practice, however, it is far more unlikely.
As the BBC's North America reporter Anthony Zurcher points out, "if this were a Democratic-controlled House of Representatives, articles of impeachment would likely be in the drafting process".
The fact is, they are not. Republicans control both the House and the Senate.
The vast majority of Republicans have remained loyal to President Trump and his approval ratings are remarkably stable, according to the Pew Research Center this month.
Of course, there are the notable exceptions, such as Senator John McCain who likened the scandals surrounding the president to the Watergate crisis.
While some Republican politicians will play down each and every bump in the road, others standing in the mid-term elections in November will wonder if having Mr Trump as leader will hurt their chances.
Finally: just how did Mr Nixon avoid impeachment?
He did what every sensible person does when they know the tide has turned against them. He quit.