In a blistering statement to reporters before the impeachment trial began on Saturday morning, Sen. Sherrod Brown, D-Ohio, called his GOP colleagues "spineless" for being poised to vote not to convict Trump out of fear he will campaign against them.

"It's so clear this president abused his power," Brown said. "It's so clear he incited violence. And my colleagues just refuse to see it because of their abject fear of Donald Trump."

"I've watched my spineless colleagues walk around with fear in their eyes for four years," Brown later continued. "And so maybe I shouldn't be surprised."

-ABC News' Benjamin Siegel

After Lead House impeachment manager Rep. Jamie Raskin, D-Md., called to subpoena Rep. Jaime Herrera Beutler, R-Wash., and Trump's defense team slammed the notion, the Senate moved to vote on calling witnesses in Trump's second impeachment trial.

In a rebuttal to the House managers requesting to subpoena GOP Rep. Jamie Herrera Beutler, R-Wash., as a witness to the impeachment trial, Trump's defense team scoffed at the idea and threatened to call 100 witnesses in response, and said the trial should wrap "today."

"They didn't put the work in that was necessary to impeach the former president," Trump's defense lawyer, Michael van der Veen argued. "But if they want to have witnesses, I'm going to need at least over 100 depositions, not just one."

"We should close this case out today," van der Veen later continued.

Lead House impeachment manager Rep. Jamie Raskin, D-Md., has called to subpoena Rep. Jaime Herrera Beutler, R-Wash., who tweeted out a statement Friday reiterating comments she made about a talk she had with House Minority Leader Kevin McCarthy regarding Trump's involvement in the Capitol siege.

In the statement, Herrera Beutler reiterated her claims which she made earlier to Washington newspaper The Daily News that McCarthy spoke to Trump as violent protesters stormed the Capitol on Jan. 6, but the then-sitting president refused to stop them.

"For that reason, and because this is the proper time to do so under the resolution that the Senate adopted to set the rules for the trial, we would like the opportunity to subpoena Congresswoman Herrera regarding her communications with House Minority Leader Kevin McCarthy, and to subpoena her contemporaneous notes that she made, regarding what President Trump told Kevin McCarthy in the middle of the insurrection," Raskin said.

Herrera Beutler ended her statement Friday by challenging those with firsthand knowledge of Trump's actions during the Capitol siege -- including former Vice President Mike Pence -- to come forward.

"To the patriots who were standing next to the former president as these conversations were happening, or even to the former vice president: if you have something to add here, now would be the time," she wrote.

Raskin said they are prepared to proceed via Zoom and then to proceed to the next phase of the trial, "including the introduction of that testimony shortly thereafter."