Trump impeachment trial live updates: Biden says charge 'not in dispute' in 1st comments on acquittal

Rep. Adam Kinzinger, R-Ill., who voted in the House to impeach President Donald Trump, told ABC News Live Prime anchor Linsey Davis that he believes it is possible, but not likely, that more Senate Republicans will vote to convict Trump. Kinzinger estimates there will not be enough to get to 67 votes, though he also said if the Senate impeachment vote was held in private, he believes it would "certainly" pass.

"I think over time, people are going to wake up to really how bad, at least, the tone was in the last four years, particularly Jan. 6, and I don't think history is going to judge too kindly those that stood by and picked politics over that oath-keeping decision," Kinzinger said.

The Republican congressman also discussed the future of the GOP and said that if the party continues to go in the direction he feels it's going in, he wouldn't be able to "stay under the Republican banner."

"I'm determined to fight for my party, but if it continues down this track, and there's no hope for it. I certainly wouldn't be able to stay under the Republican banner as much as I want to, you know, I need to be associated with a party that's optimistic about the future," Kinzinger said. "And I'm not there yet. I'm going to fight for the soul of this party and down the road, hopefully, that won't be a decision I'll have to make."

-ABC News' Jon Schlosberg

The Senate kicked off former President Donald Trump's second impeachment trial on Tuesday with Democrats using a 13-minute video of the Jan. 6 Capitol riot to help make their case to the Senate, and Trump's defense team debating the constitutionality of the trial of a former president.

Here are three takeaways from the first day of arguments, which ended with the Senate voting 56-44 to proceed with the trial.

Trump's legal team, including Bruce Castor Jr., a former district attorney of Montgomery County, Pennsylvania, made a poor first impression in a 48-minute argument that garnered criticism from senators who found themselves confused and unimpressed.

Senators, many of whom were in the Capitol during the Jan. 6 riots, relived the attacks during a documentary-style video of the Capitol riot, a harrowing presentation that meshed C-SPAN footage of staid House and Senate floor debates with gritty, expletive-laden riot footage and some of the former president's social media posts.

Democrats also cited conservative lawyers who backed the trial, saying that not trying Trump would suggest to future presidents that they would not be held accountable for their actions during their final days in office.

-ABC News' Benjamin Siegel

On Wednesday, the House impeachment managers must file all motions, except those related to witnesses by 9 a.m. and the Trump legal team must to respond to the House managers’ motions by 11 a.m.

The trial will resume at noon on Wednesday with arguments and a vote for any motions made by either side.

After that, opening arguments begin. The House impeachment managers have up to 16 hours over two days, though both sides are limited to eight hours of arguments each day.

-ABC News' Trish Turner

ABC News' Congressional Correspondent Rachel Scott senators on both sides of the aisle looked confused as Trump attorney Bruce Castor spoke for the defense team -- a feeling perhaps shared by the former president who aides told ABC News was unhappy with Castor's performance.

"They were antsy," Scott said of the senators during Castor's remarks, "So much so that several actually got up and left and went to a different gathering place and left the room empty."

She said once David Schoen took over, the senators appeared more attentive to the defense' team's performance.

"But there was a stark contrast to when House Democrats got up to make their arguments when they played that 13-minute long video and there was complete silence in the chamber, so much so that you heard the echoes from the sound from the violent mob that stormed the Capitol that day bouncing off the chamber walls," Scott said.

Scott said that although Democrats may have compelling arguments, the majority of Republicans have already signaled they won't vote to convict Trump. Democrats would need at least 17 Republicans to side with them -- an increasingly difficult feat after Tuesday evening's vote in which 44 Republicans voted the trial was unconstitutional.

"You may have some Republicans who may be moved by the presentation by Democrats they may feel compelled by it. They may be shocked to see what they are seeing before their eyes, what they witnessed watching those events replay for them. But at the end of the day, Democrats are going to need the support of at least 17 Republicans in order to convict Donald Trump and already so many have blasted this process as unconstitutional," Scott said.