Trump became only the third USA president to be impeached on December 18 when the House voted to formally charge him with illicitly seeking help from Ukraine for his reelection campaign this year.
The House will also have to vote to approve the names of the House lawmakers who will serve as "managers" in the Senate trial.
The case against Trump is focused on a July 25 telephone call in which he asked Ukrainian President Volodymyr Zelensky to open a corruption investigation into Biden and his son Hunter, and into a discredited theory that Ukraine, not Russian Federation, meddled in the 2016 USA election. He, along with the other senators running for president in 2020, will be stuck in Washington for a six-days-a-week trial instead of campaigning for the nation's first presidential caucus, to be held February 3. The first article charges Trump with abusing the power of his office for attempting to pressure Ukraine to investigate a potential political opponent, former Vice President Joe Biden; the second charges Trump obstructed Congress' investigation of his actions.
A key question looming over the trial is to what extent the president will seek to influence the proceedings and limit witnesses who have direct knowledge of events at the center of the inquiry.
"Look, we're happy for anyone to come forward and testify", Gidley said on Fox News' "Fox and Friends."
"It will fall to the Senate to end it with seriousness and sobriety", he said. They indicated that they'd rather get on with the trial.
A two-thirds majority would be required to convict Trump and remove him from office, which is considered unlikely in a Senate where Republicans outnumber Democrats 53 to 47.
"I think our members, generally are not interested in the motion to dismiss".
They also want documents related to the charges that Trump refused to hand over to the House probe. Republican allies led by McConnell, R-Ky., are ready to deliver swift acquittal without new testimony. That would only require a majority vote. Todd Young of IN and Susan Collins of ME said Tuesday they will support it.
The White House has confirmed its defence team for the Senate trial.
Democrats grew frustrated with Pelosi's approach, with several Senate Democrats arguing publicly that there was no further leverage to be had by holding the articles.
"We want the truth", Senate Minority Leader Chuck Schumer said Tuesday as the chamber opened.
Last week, McConnell announced that he has enough Republican votes to adopt trial rules that don't immediately allow witnesses.
"The Senate will not be sucked into this precedent-breaking path".
McConnell is drafting an organizing resolution that will outline the steps ahead. Why say more about the need for them to give sworn testimony, notwithstanding the president's continuing, and obviously suspicious, invocation of various "executive privileges" to silence them for the supposed benefit of future presidents? McConnell is hesitant to call new witnesses who would prolong the trial.
The 1999 impeachment trial of then-President Bill Clinton lasted five weeks.
By voting in favor of calling witnesses and demanding documents, Democrats will necessarily take the chance that the information revealed will help exonerate the president.
While some Democrats have grumbled about the delay, Pelosi and other party leaders defended the strategy, saying it produced new potential evidence and turned public attention on the upcoming trial. Democratic voters favored the idea the most (91 percent), followed by independents (71 percent) and Republicans (39 percent). Graham and Sen. Josh Hawley, R-Mo. are leading the effort to dismiss the charges against Trump. She and the others appear to be gathering support.
House Democratic Chief Deputy Whip Henry Cuellar (D-Texas) told reporters just before the press conference that Pelosi was in charge of appointing the House managers.