Trump impeachment trial live updates: Biden makes 1st comments on acquittal

The Senate voted 56-44 to proceed with the impeachment trial.

Six Republican senators voted with Democrats that the trial is constitutional. Last month, 45 Republican senators voted to dismiss the trial in an effort led by Republican Sen. Rand Paul of Kentucky.

Before the Senate began voting, Rep. Jamie Raskin, D-Md., waived the House impeachment managers' remaining time and said, "nothing could be more bipartisan than the desire to recess."

The trial is adjourned until noon Wednesday.

In an intense, gloom-filled presentation, Trump attorney David Schoen called the trial of the former president an “irretrievably flawed process” that “we all will regret forever” and leave a lasting “stain” on the Senate.

Multiple times, he called the impeachment proceedings "a dangerous snap impeachment."

Schoen warned that Democrats were intent on going after Trump to deprive him from office “in the name of the Constitution.”

“But this is an affront to the Constitution, no matter who they target today. It means nothing less than the denial of the right to vote and the independent right for a candidate to run for elected political office guaranteed by the First and 14th Amendments to the United States Constitution, under the guise of impeachment as a tool to disenfranchise," he said, at one point holding up a copy of the document.

In arguing against the House managers’ claim that the trial is constitutional, Schoen continued a line of argument that Trump attorney Bruce Castor started -- that if Trump had done anything wrong, like incitement, then a criminal court proceeding is the correct remedy.

“The risk to the institution of the presidency and to any and all past officers is limited only by one's imagination. The weakness of the managers' case is further demonstrated by the reliance of unproven assertion that if President Trump is not impeached, future officers who are impeached will evade removal by resigning, either before impeachment or Senate trial," he said. "We have a judicial process in this country. We have an investigative process in this country to which former office holder is immune. That's the process that should be running his course.”

Schoen suggested that House Speaker Nancy Pelosi intentionally delayed the article -- and in doing so, did harm to Trump, since the Chief Justice, an impartial arbiter, cannot preside, making the trial unconstitutional, he said.

Instead, Schoen said, a partisan Sen. Patrick Leahy, D-Vt., is judging Trump -- a partisan who Schoen noted has taken a position on impeachment already.

-ABC News' Trish Turner

Both Trump's legal defense and the House managers have wrapped up their arguments over the constitutionality of the impeachment.

The Senators are voting on whether or not the trial is constitutional.

Trump lawyer David Schoen, expanding on Bruce Castor's argument that the U.S. wasn't meant to follow the "British model," argued House Democrats held the impeachment article against Trump and forced an "intentional delay."

However, Senate Minority Leader Mitch McConnell told soon-to-be Majority Leader Chuck Schumer he wouldn't bring the Senate back from recess early, in part, so that Trump's defense team could have time to prepare.

Schoen argued in his opening remarks that the nation cannot heal from the attack and unify so long as the trial moves forward, calling on senators to vote that the trial is unconstitutional in a vote later Tuesday because, he said, the trial lacks due process.

"They say you need this trial before the nation can heal, that the nation cannot heal without it. I say our nation cannot possibly heal with it," he said.

Schoen also stated as fact that "the trial in the Senate of a private citizen is not permitted" and said that only a "sitting president can be convicted and impeached," pointing to how Supreme Court Chief Justice John Roberts isn't presiding over the trial. However, Democrats cited legal scholars in their opening arguments debating the opposite.

"Trial by the Senate sitting at the court of impeachment is reserved for the president of the United States, not a private citizen who used to be president of the United States," he said. "This is the first time that the United States Senate has ever been asked to apply the constitution's textual identification of 'the president' and impeachment provisions to anyone other than the sitting president of the United States."

At one point, Schoen criticized House managers for, he said, using "a movie company and a large law firm" to package a video of the Jan. 6 Capitol attack to "chill and horrify you."

He went on to play a video accompanied with ominous music of Democrats calling for Trump's impeachment.

-ABC News' Benjamin Siegel