New York, Feb 13 (IANS): The second impeachment trial of former US President Donald Trump resumed on Saturday with the Senate voting to call witnesses as requested by the Democratic prosecution, upending the expectations that the process would wind up quickly.

Jamie Raskin, the lead prosecutor, asked to call Republican Representative Jaime Herrera Beutler who had claimed that a fellow Republican had told her that when he spoke to Trump about the rioters breaking into the Capitol, the latter appeared to condone the attack.

The Senate voted 55-45 to allow calling witnesses. One of the strong supporters of Trump, Lindsey Graham, joined the Democrats and party dissenters to support calling the witnesses, possibly laying the ground for Trump's lawyers to do the same.

The move opens the way for an extended trial that was expected to wind up on Saturday with the closing arguments and a vote on the charges against Trump, allowing it to proceed with President Joe Biden's agenda.

Trump's lawyer Michael van der Veen said that he wants to call at least 100 witnesses, including Speaker Nancy Pelosi and Vice President Kamala Harris.

Beutler said on Friday night that Kevin McCarthy, the Republican leader in the House of Representatives, had told her that when he asked Trump "to publicly and forcefully call off the riot", he replied, "Well, Kevin, I guess these people are more upset about the election than you are."

Raskin has not indicated that he would call McCarthy to be a witness.

Trump was impeached last month by the House on a charge of inciting the riot on January 6 when some of his supporters stormed the Capitol. The Senate began a judicial-style trial on the charge with Senators sitting as jurors.

A two-third majority of Senators will have to vote to convict Trump in the chamber that is split 50-50. Only six Republicans appeared willing to cross the floor to convict Trump, making the trial a media spectacle for the political benefit of the Democratic Party rather than an action to impose a penalty on Trump.

Republican leader in the Senate, Mitch McConnel, has told his fellow Republicans that he would vote to acquit Trump, making it unlikely that Democrats would get 11 more Republican senators to join them for the two-third majority of 67.

Trump's lawyers had wound up their defence on Friday without taking up the 16 hours over two days allowed to them, mainly making the case that Trump's statements calling the election of Joe Biden illegal because he claimed there was massive fraud and his exhortations to his supporters to protest was an exercise of his constitutional right to free speech.

Biden has indicated that he would like the impeachment trial to end soon so that he could get on with the important task of confirming his key nominees to the administrative posts. Republican leaders also wanted the trial to end quickly so that they could move past Trump's disruptive legacy.

The Senate will have to decide on how to have the witnesses to testify in the age of Covid-19 and if they can testify through a video link.

The Democrat prosecution -- known technically as impeachment managers -- used their allotted 16 hours using dramatic videos of the mob attack interspersed with clips of Trump riling up his supporters.