Senators were settling in for a long day of constitutional arguments for impeachment Thursday afternoon when a familiar sound snapped the room to attention: the voice of President Donald Trump.
Republicans and Democrats turned to face the bank of television screens in the chamber as Rep. Adam Schiff teed up a now-infamous clip of Trump telling reporters in October that he had hoped Ukrainian President Volodymyr Zelenskiy would open a probe into the Biden family.
It was a vivid example Thursday of how Democrats are using an unprecedented number of video clips of congressional hearings, White House news conferences and, most notably, Trump himself, in an effort to hammer home their argument for removing the president from office.
Denied the opportunity to question witnesses by Senate Republicans, Democrats have played more than 140 video clips over two days of opening arguments, bringing the president, his associates and administration officials into the chamber.
They've played snippets of Trump's remarks on the White House North Lawn in October -- when the president told reporters he wanted Ukraine to investigate the Bidens and that China should as well -- at least half-a-dozen times.
MORE: Trump says Ukraine, China should investigate Bidens, Pence comes to his defense"It's stunning," Sen. Chris Coons, D-Del., said of the sensation of watching Trump -- in his own words -- from his desk in the Senate chamber.
Republican managers in the trial of President Bill Clinton 21 years ago used video in their arguments and senators watched videotaped witness depositions later in the proceedings. But no case for a president's impeachment has ever relied so heavily on hearing and seeing the president, his top aides and other key witnesses -- or the ability to repeatedly project them to the full Senate and to the public to reinforce their presentations.
"Their use of video has been incredibly effective," Sen. Chris Murphy, D-Conn., said Wednesday evening. "I've been very impressed at the way they've told the story, and I think it's really hard for Republicans to hear it all in one place."
"They've done a good job of presenting," Sen. Lamar Alexander, R-Tenn., a retiring moderate who some Democrats believe could be persuaded to support calling witnesses, told reporters Thursday. "We have a lot to consider."
Unlike Clinton, who tried to limit commenting on his impeachment and the allegations against him as the process unfolded, Trump is a voracious consumer of news who makes his case repeatedly on social media each day. He weighed in on a near-daily basis as House Democrats continued to investigate the Ukraine affair last year.
MORE: Day 2 of Democrats laying out their impeachment case: 3 things to know"It's important to bring that evidence and testimony to life for the senators," Rep. Hakeem Jeffries, D-N.Y, an impeachment manager, told ABC News after the first day of arguments.
Republicans, including some who have been critical and skeptical of the Democrats' case, have acknowledged the effectiveness of the clips and other exhibits, including text message exchanges and emails obtained by House investigators.
"It gets people's attention, sure," Sen. Roy Blunt, R-Mo., told ABC News.
"Is there new information, since I didn't watch television of the House hearings? Am I seeing stuff I didn't see before? Yeah," Sen. Bill Cassidy, R-La., told ABC News. "But, of course, you also want to see what the rebuttal arguments are."
Others say the Democrats' exhibits haven't affected their opinions about the case against the president, and criticized Democrats for being repetitive.
"It's not really changing our opinion, we're just hearing that same message," Sen. Joni Ernst, R-Iowa, said Thursday.
Sen. Ron Johnson, R-Wis. was more blunt.
"There's nothing new that really adds to their case," he said. "We shouldn't even be in an impeachment inquiry."
MORE: Trump's impeachment trial: How we got here, what happens next and what to watchBeyond the captive audience in the Senate chamber, Democrats, including the House managers, have said they're trying to reach the American people, and continue to make the case that Trump abused his power.
While Democrats privately admit that persuading 20 Republicans to join them in voting to convict Trump is unlikely, they are more hopeful that the four moderate GOP senators Democrats have targeted could be convinced -- either by the managers' presentations or constituents -- to bring additional evidence and witnesses into the trial.
"It may have an effect on them," Senate Minority Leader Chuck Schumer, D-N.Y., said Wednesday of the managers' use of video. "But even if it doesn't, I bet tonight had an effect on the public, and that redounds to some Republicans."
ABC News' Trish Turner contributed to this report.