At the close of the evening, US Representative Adam Schiff made an emotional plea to senators to consider what was at stake as President Trump stands accused of seeking a Ukrainian probe into political foe Joe Biden and his son.
Democratic House prosecutors made an expansive case late on Thursday at Donald Trump's impeachment trial that he abused power like no other president in history, swept up by a “completely bogus” Ukraine theory pushed by attorney Rudy Giuliani.
On Friday, the Democrats will press their final day of arguments before sceptical Republican senators, focusing on the second article of impeachment, obstruction of Congress' investigation.
As the audience of Senate jurors sat through another long day, and night, the prosecutors outlined the charge.
They argued that Trump abused power for his own personal political benefit ahead of the 2020 election, even as the nation's top FBI and national security officials were publicly warning of the theory that it was Ukraine, not Russia, that interfered in the 2016 election.
“That's what Donald Trump wanted investigated or announced – this completely bogus Kremlin-pushed conspiracy theory,” said Adam Schiff, the chairman of the House Intelligence Committee who is leading the prosecution, during Thursday's session.
At the close of the evening, Schiff made an emotional plea to senators to consider what was at stake as Trump is accused of seeking Ukrainian probes of political foe Joe Biden and Biden's son while holding back congressionally approved military aid as leverage.
“Right matters,” he said, quoting Army officer Lieutenant Colonel Alex Vindman who had testified in the House. “Otherwise we are lost.”
The president is facing trial in the Senate after the House impeached him last month, accusing Trump of abusing his office by asking Ukraine for the Biden investigation while withholding the aid from a US ally at war with bordering Russia. The second article of impeachment accuses him of obstructing Congress by refusing to turn over documents or allow officials to testify in the House probe. Arguments addressing this will be heard on Friday.
Republicans, growing tired of the long hours of proceedings, have defended Trump’s actions as appropriate and cast the process as a politically motivated effort to weaken him in the midst of his reelection campaign. Republicans hold a 53-47 majority in the Senate, and acquittal is considered likely.
The Democrats' challenge is clear as they try to convince not just fidgety senators but an American public divided over the Republican president in an election year.
With Chief Justice John Roberts presiding, Democrats argued on Thursday that Trump's motives were apparent.
The Biden investigation
“No president has ever used his office to compel a foreign nation to help him cheat in our elections,” Jerrold Nadler of New York, the chairman of the House Judiciary Committee, told the senators. He said the nation's founders would be shocked. “The president's conduct is wrong. It is illegal. It is dangerous.”
Democrats scoffed at Trump's claim he had good reasons for pressuring Ukraine to investigate Biden or other political foes.
Representative Sylvia Garcia of Texas, herself a former judge and now one of the impeachment managers, said there is “no evidence, nothing, nada” to suggest that Biden did anything improper in dealings with Ukraine.
Trump, with Giuliani, pursued investigations of Biden and his son, Hunter, who served on a Ukrainian gas company’s board and sought the probe of debunked theories of what nation was guilty of interference in the 2016 US election.
On dual tracks, Democrats prosecuted their case while answering in advance the arguments expected from the president’s attorneys in the days ahead.
'No specific crime'
At one point, the Democrats showed video footage of a younger Lindsey Graham, then a South Carolina congressman and now a GOP senator allied with Trump, arguing during Bill Clinton's 1999 impeachment that no crime was needed for impeaching a president.
Trump’s defence team is now arguing that the impeachment articles against him are invalid because they do not allege he committed a specific crime.
The president's defenders' turn will come on Saturday.
“We will be putting on a vigourous defence of both facts, rebutting what they said” and the Constitution, said attorney Jay Sekulow.
Ahead of the day's proceedings, Senator Roy Blunt of Missouri said the Democrats were putting forward “admirable presentations.”
But he said “there’s just not much new here”.
During the dinner break, Senator John Barrasso said it seemed like “Groundhog Day in the Senate”.
Top Senate Democrat Chuck Schumer acknowledged that many senators “really don't want to be here”.
But Schumer said Schiff has been outlining a compelling case that many Republicans are hearing it for only the first time. He contended they can't help but be “glued” to his testimony.
Once reluctant to take on impeachment during an election year, Democrats are now marching toward a decision by the Senate that the American public also will judge.
Trump blasted the proceedings in a Thursday tweet, declaring them the “most unfair and corrupt hearing in Congressional history.”
After the House prosecutors finish, the president's lawyers will have as long as 24 hours.
It's unclear how much time they will actually take, but Trump's team is not expected to finish Saturday, according to a person unauthorised to discuss the planning and granted anonymity. The Senate is expected to take only Sunday off and push into next week.
After that senators will face the question of whether they do, or do not, want to call witnesses to testify.
Senators were permitted on Thursday to review supplemental testimony submitted by an aide to Vice President Mike Pence, Jennifer Williams, who was among those who had concerns about Trump's actions. Democrats said the testimony, which is classified, bolsters their impeachment case. A lawyer for Williams declined to comment.
Holding the room's attention has been difficult for the Democrats, but senators seemed to pay closer mind to Schiff's testimony that grew dramatic.
Most senators, even Republicans, sat at their desks throughout the afternoon session, as the rules stipulate, and not as many of them were yawning or standing to stretch as during the previous long nights.
To help senators pass the time, the Republican chairman of the Senate Intelligence Committee, Richard Burr of North Carolina, passed out lunch favours of fidget spinners, stress balls and other toys.
Democrats thanked the senators for their time and patience, acknowledging the repetition of some of their presentations.
The impeachment trial is set against the backdrop of the 2020 election.
Four senators who are Democratic presidential candidates are off the campaign trail, seated as jurors.
To remove or not to remove Trump
A new poll from The Associated Press-NORC Centre for Public Affairs Research showed the public slightly more likely to say the Senate should convict and remove Trump from office than to say it should not, 45 to 40 percent.
But a sizable percentage, 14 percent, said they didn't know enough to have an opinion.
One issue with wide agreement: Trump should allow top aides to appear as witnesses at the trial.
About 7 in 10 said so, including majorities of Republicans and Democrats, according to the poll.
The strategy of more witnesses, though, seemed all but settled.
Republicans rejected Democratic efforts to get Trump aides including former national security adviser John Bolton and acting chief-of-staff Mick Mulvaney to testify in back-to-back votes earlier this week.
Senators were likely to repeat that rejection next week.