U.S. Democrats on Thursday vowed to keep fighting to hear witnesses at President Donald Trump's pending impeachment trial in the Republican-controlled Senate, even as their drive to exact a guarantee ahead of the proceedings appeared futile.
Senate Democratic leader Chuck Schumer said he will press Republicans accept four witnesses including John Bolton, Trump's former national security adviser, even if the Senate votes not to accept testimony at the start of the trial to determine whether Trump should be convicted of abusing his power and obstructing Congress over Ukraine.
"Those votes at the beginning of the trial will not be the last votes on witnesses and documents. Make no mistake, we will continue to revisit the issue," Schumer said on the Senate floor.
Schumer, who needs only four of the 100-seat Senate's 53 Republicans to join Democrats on the witness question, could succeed by pressuring vulnerable Republicans, such as Senator Susan Collins and Senator Cory Gardner, who face reelection in swing states in November.
Without witnesses, Democrats fear Senate Republicans could move quickly to dismiss the charges against Trump.
But securing witnesses could open up a Pandora's box for Democrats. Trump said he would like to hear from Biden, his businessman son Hunter Biden, House Intelligence Committee Chairman Adam Schiff and the anonymous whistleblower whose complaint launched the impeachment inquiry.
Trump also said he might try to block Bolton from testifying.
"When we start allowing national security advisers to just go up and say whatever they want to say - we can't do that," he told reporters at the White House.
The timing of Trump's Senate trial remained up in the air, as House of Representatives Speaker Nancy Pelosi said she wants to first see Senate Republican Leader Mitch McConnell's trial plan before sending the impeachment articles to the Senate.
"I'll send them over when I'm ready, and that will probably be soon," she told a news conference.
But with some Senate Democrats calling for the trial to move forward, expectations have risen for a break in the impasse.
"I want to give Speaker Pelosi the time to make the right judgment in terms of reporting this to the Senate. I expect it to happen soon," Senator Richard Durbin, the chamber's No. 2 Democrat after Schumer, told Reuters.
Senate Republican Leader Mitch McConnell told other Republican lawmakers he expects to get the articles as soon as Friday, which would set up a trial for next week, according to a source familiar with the discussion.
The Democratic-controlled House impeached Trump in December on charges that he abused his power for personal gain by pressuring Ukraine to announce a corruption investigation of former Vice President Joe Biden, a leading contender for the Democratic nomination to face Trump in November's presidential election.
The House also charged him with obstructing Congress by directing administration officials and agencies not to cooperate with the impeachment inquiry.
Trump says he did nothing wrong and has dismissed his impeachment as a partisan bid to undo his 2016 election. He is likely to be acquitted, as no Republicans have voiced support for ousting him from office.
McConnell wants to consider calling witnesses well after the proceedings begin, and has support from enough Republican lawmakers to adopt his plan without backing from Democrats.
McConnell said the Senate would resume its regular legislative business next week if the impeachment articles are not in hand.
"This conversation is over," McConnell said on the Senate floor. "We are not ceding our constitutional authority to the partisan designs of the speaker."
At a meeting with Trump on Wednesday, McConnell walked the president through his intended impeachment trial format, according to a person familiar with the discussion. But the Republican leader has neither shared text of the planned trial resolution with Trump nor negotiated with the White House on how the measure would be worded, the source said.