Nine members of the United States House of Representatives walked to the Senate on Monday evening and delivered a document calling for the trial of former US president Donald Trump.

The Senate accepted the document, known as the article of impeachment, and set Feb 9 for beginning the trial, making Trump the second president in US history to face such a trial and the only to face it twice.

In an interview to CNN, US President Joe Biden said he was aware that the trial could have repercussions but "I think it has to happen. There would be a worse effect if it did not happen."

But South Carolina Senator Lindsey Graham, a strong Trump ally, said the impeachment move should have been "dismissed" because of a "constitutional lack of jurisdiction".

Trump, who has not yet commented on the proceedings, is still assembling a legal team for the trial. A South Carolina lawyer Butch Bowers could lead the defence team.

Congressman Ted Lieu, one of the nine who brought the article to the Senate, described the procession as "historic". All nine are now known as House managers who will represent the House during the trial.

Congressman Jamie Raskin, the lead House impeachment manager, turned towards his colleagues as they lined up for the walk, and said, "proud of you guys."

There were only a few Republicans in the Senate, including Senators Mitch McConnell and Mitt Romney, when the procession arrived. Democrat Patrick Leahy, the president pro tempore of the Senate, was presiding over the session.

The 100-member Senate is equally divided between Republicans and Democrats. Since Vice President Kamala Harris, a Democrat, has a tie-vote, Democrats now control the Senate.

A two-thirds majority is required to convict Trump. So, Democrats need to win over 17 Republicans for their move to succeed. If convicted, a simple-majority vote could bar Trump from holding federal office again.

Explainer: What does impeachment mean for Trump's future?

On Jan 13, when the House impeached Trump for a second time by 232 to 197 votes, 10 Republicans voted against Trump.

The impeachment article charges Trump with "incitement of insurrection" for his role in the deadly Capitol riots. The article also cites Trump's Jan 2 phone call to Georgia Secretary of State Brad Raffensperger, urging him to "find" enough votes to overturn the state's election results. The House called it an effort "to subvert and obstruct the certification of the results of the 2020 presidential election".

According to US media reports, President Biden had asked House Democrats to delay the trial as he needed more time to settle down and needed Republicans’ support for a smooth endorsement of his nominees. All senior nominees require the Senate’s confirmation. Biden also needs support for the passage of his huge coronavirus relief package.

In his brief interview to CNN, President Biden said he does not think 17 Republican senators will vote to convict Trump. "The Senate has changed since I was there, but it hasn't changed that much," Biden said.

Senate Majority Leader Chuck Schumer, now a Democrat, stressed the need for the trial but said the process must move fast. "Everyone wants to put this awful chapter in American history behind us. But sweeping it under the rug will not bring healing," he said.

Republican Senator Marco Rubio told Fox News that while he believes Trump "bears responsibility for some of what happened," the trial would only increase tensions. "We're just going to jump right back into what we've been going through for the last five years and bring it up with a trial and it's going to be bad for the country," he said.

Comparison with crowd at riot

Yet, on Monday evening, all eyes were focused on the Capitol as television commentators compared this small procession with the huge crowd that invaded the building on Jan 6, causing five deaths.

Unlike the Trump crowd, they had no weapons. No scaffoldings. No pictures and no banners. There was no slogan chanting. No threats hurled.

But this small group had the power of the US Constitution behind it. So, the two-page document carried across the rotunda had immensely more power than slogans chanted inside the building on Jan 6 to stop the counting of the electoral votes.

It also carried more weight than the empty threats Trump made on Jan 6 that caused the crowd to ransack the Capitol.

The US Constitution requires the chief justice to preside over the trial when a president is impeached but Justice John Roberts has opted out, saying that Trump is no more a president.