For the first time in history, a US president is due to be tried by members of the country’s upper house for the second time.
Such was the anger among Democrats at the storming of the Capitol building in early January, they voted to impeach Donald Trump again, after the first impeachment vote in 2019 failed to convict him.
Amid the anger, it is a risky strategy: There were some who felt Mr Trump’s escape from censure when he faced senators last time round invigorated his particular brand of conservatism, fuelling America’s divisions.
Last time, the 45th president faced accusations of abusing his power by pressuring Ukraine to investigate Joe Biden. At the time, the now 46th president was just a potential opponent in that year’s presidential election. Mr Trump was acquitted by a majority of 52:48 for one charge and 53:47 for the second. Only one Republican voted against him on one of the charges.
At stake this time is not whether Mr Trump remains in office, as it was 12 months ago. He has left the White House. But, such is the fury at his four years in power, Democrats want to make sure he is barred from running from federal office again.
So, what can we expect this time?
1. A different charge
In 2020, Mr Trump faced two charges. 1. Abuse of power and 2. Obstruction of Congress.
The accusation this time around is that President Trump, engaged in an “incitement of insurrection”, because his words encouraged the most violent attack on Congress in more than 200 years, in which five people died, including a police officer.
2. Probably no Trump at all
Last time, the president stayed in the White House or was travelling around the US and didn’t attend the hearing, presumably claiming he was too busy running the country.
This time it might be expected that, as he is no longer commander-in-chief, he might pop down to the Senate chamber to hear the arguments against him. But that is not so, say analysts predicting what is going to happen.
The most likely location from where he will observe what is taking place, if anywhere, will be his Mar-a-Lago resort in Florida, where he has been since he left Washington DC and where he has been seen playing golf.
How the storming of the Capitol unfolded
He was requested to testify, but his lawyers refused on his behalf.
And, compared to last time, when he provided regular commentary through his Twitter feed, trial watchers may have to tune into the lesser-known platform Gab, as the former president has since been suspended from other social media.
3. It shouldn’t last as long, in theory
The last trial, just over a year ago, lasted a total of two weeks and six days.
This time analysts say the proceedings are expected to diverge from the lengthy, complicated trial that resulted in an acquittal.
Experts say the trial could be over in half the time, but it may be complicated by other events. A one-day pause will last from Friday evening to Saturday evening in order to allow a Trump lawyer to observe the Jewish Sabbath and the Senate is not currently scheduled to be in session during the week starting 15 February.
Details of the proceedings are still being negotiated by the Senate leaders, with the length of opening arguments, questions and deliberations all up for discussion.
4. Not many, if any, witnesses
The US news agency AP says it appears there will be few witnesses called, with prosecutors and defence lawyers instead speaking directly to senators
This is unsurprising as most of the senators, who have sworn to be impartial, are are actually among the witnesses to the siege. In fact, many fled for their safety as the rioters broke into the Capitol and temporarily halted the electoral count certifying Joe Biden’s victory.
5. Prosecutors using emotional appeals
So, without the need to cross examine witnesses to a largely secret event, as was the conversation Mr Trump had in which he was said to have solicited a “quid pro quo” arrangement with Ukraine president Volodymyr Zelenskiy, prosecutors are this time expected to use a mass of video evidence of events during and before the Capitol storming.
Adam Schiff, the Democratic Congressman who led the prosecution against Mr Trump in 2020, said: “There will already be over 100 witnesses present”, referring to the senators in the chamber.
Mr Trump’s tweets and other statements in public will also be under scrutiny, with House managers leading the prosecution likely to present the former president’s incendiary rhetoric refusing to concede the election.
6. Defence to emphasise procedure
Mr Trump’s new defence team says it plans to hit back at prosecution attempts to sway senators with its own array of videos of Democratic politicians making fiery speeches of the type they accuse Mr Trump of making.
They will also pick apart justification for the impeachment trial, claiming that it is unconstitutional. It will expand on a line of attack that has already proved successful, with an earlier vote to set the impeachment aside as unconstitutional because the presidentis no longer in office, winning the support of 44 other Republican senators.
Their arguments are likely to underline the importance of free speech in the US constitution, with comments from Senator Paul Rand possibly hinting at some of the themes when he said: “If we’re going to criminalize speech, and somehow impeach everybody who says, ‘Go fight to hear your voices heard’, I mean really we ought to impeach Chuck Schumer then.”
Finally, they have said that they will assert that supporters of Mr Trump who stormed the Capitol did so of their own accord, not because Mr Trump encouraged them to.
7. Acquittal likely, but Republicans split
The vote last month to set aside the trial in which just five senators joined Democrats in the upper house to reject it has left many observers feeling a guilty verdict has little chance of success.
In order to be convicted, 67 senators have to find Mr Trump guilty – with at least 17 of those being Republican, assuming all 50 Democrats in the Senate vote to convict.
While some of those who voted to set aside the impeachment trial in January have said they continue to have an open mind, most are expected to back the former president.
According to the Washington Post on 26 January, 37 Republican senators are opposed to conviction – enough for Mr Trump to be acquitted.
8. Impact to be felt for some time
If Mr Trump is convicted, it will still take another vote – this time by simple majority – to bar him from running for office again. He can still, of course, remain involved in politics in other ways – as a figurehead for the form of politics he has branded as his own during the last five years. There are rumours he will continue in television. His family may also run for office.
But, if he is acquitted again, some Democrat-leaning commentators are concerned there may be greater consequences.
Some say an acquittal could be interpreted as a condonance of not just the actions of Mr Trump, but potentially anyone who advanced similar points of view, however wrong. And, in America’s currently febrile political atmosphere, this could have an unpredictable legacy.
It could also have a impact on the Grand Old Party (GOP), as the Republicans are known, which is already at risk of splintering over whether to persist with Trumpism, or to reclaim its traditional, more internationalist values.
Liz Cheney, the daughter of former vice president Dick Cheney and currently House Republican Conference Chair – the third-highest position in the House Republican leadership – has already faced an attempt to remove her because she supported Mr Trump’s impeachment. And there are other internal battles ongoing. Mr Trump’s escape from punishment could empower those who want the GOP to continue down the path he embarked upon.