Senate Agrees Trial Is Constitutional, as Trump Consolidates Votes for an Acquittal

Others, like Senator Mitch McConnell of Kentucky, continue to insist they will serve as impartial jurors and are open to conviction even if they voted to dismiss the case on constitutional grounds. But the two positions are difficult to reconcile.

Seventeen Republicans would have to abandon Mr. Trump to reach the two-thirds threshold to convict him. In the vote on Tuesday, the six Republicans who said the trial should go forward were Mr. Cassidy, Susan Collins of Maine, Lisa Murkowski of Alaska, Mitt Romney of Utah, Ben Sasse of Nebraska and Patrick J. Toomey of Pennsylvania.

Still, it was clear the House managers had fulfilled their goal of forcing senators to stare down the reality of what unfolded on Jan. 6 and contemplate Mr. Trump’s role in the rampage. Mr. Raskin, a former constitutional law professor, had senators sitting silently in their chamber, reliving the assault through a slickly produced video — complete with graphic scenes of violence by the rioters, who were using the kinds of expletives seldom heard on the Senate floor.

At one point, the anguished screams of a police officer were heard as he was nearly crushed by the mob at the door.

Mr. Raskin’s emotional appeal came after a lengthy legal argument in which he said that Mr. Trump and his lawyers were asking senators to create an illogical “January exception” that flew in the face of the founders’ intent. Recreating debates from the 1787 Constitutional Convention and appealing directly to senators’ common sense, Mr. Raskin argued that the Senate must not allow a president to become immune from conduct committed in his last month in office.

“Everyone can see immediately why this is so dangerous,” he said. “It is an invitation to the president to take his best shot at anything he may want to do on his way out the door, including using violent means to lock that door, to hang on to the Oval Office at all costs and to block the peaceful transfer of power.”

The words still hung in the Senate chamber as Mr. Raskin hit play on a video montage of the deadly assault, interspersing the president’s own words with footage of the pro-Trump throng mobbing the Capitol and marauding through its corridors.

“He would have you believe there is absolutely nothing the Senate can do about it,” Mr. Raskin said, gesturing at the images. “No trial. No facts. He wants you to decide that the Senate is powerless at that point. That can’t be right.”

Mr. Raskin said the framers had intended just the opposite. They had been perfectly comfortable with impeaching former officials, he said.

There were other, subtler nudges to pull Republicans into the trial. The managers repeatedly referred to conservatives’ favored approaches to analyzing the Constitution, cited legal scholars associated with the conservative Federalist Society and embraced an unlikely ally, Charles J. Cooper, an influential conservative lawyer allied with congressional leaders who made a forceful argument this week in The Wall Street Journal in favor of a trial.

As Representative Joe Neguse of Colorado walked senators through the chamber’s own precedent on the question, he said their predecessors had confronted and rejected the same argument as Mr. Trump’s in 1876.

“Literally, they were sitting in the same chairs you all are sitting in today, they were outraged by that argument,” he said, looking out at the chamber.

The arguments from Mr. Trump’s three-person defense team, installed just two weeks ago, were less cohesive.

Perhaps to his benefit, Mr. Castor took the air out of the room after Mr. Raskin’s description of Jan 6. with an ambling, and at times contradictory, monologue about the passions of the moment and senators’ love of country. After nearly an hour, he reached a conclusion, saying that as a private citizen, Mr. Trump should not be impeached, and that if the Justice Department believed he had done anything wrong, it would be prosecuting him.

“There is no opportunity where the president of the United States can run rampant in January at the end of his term and just go away scot free,” Mr. Castor said. “The Department of Justice does know what to do with such people.”

He argued that Democrats really just wanted to make sure that Mr. Trump could not run again.

Following him at the podium, Mr. Schoen took a more adversarial role. He called Senator Patrick J. Leahy, who was presiding as the Senate’s president pro tempore, a biased judge. And he said that Mr. Trump’s admonition to his supporters on Jan. 6 to “fight like hell” was protected free speech.

Mr. Schoen derided the managers for hiring a “movie company” to stitch together the most gruesome scenes of the attack as if it were a “blood sport.” But he played his own video presentation of clips of Democratic lawmakers through the years calling for Mr. Trump to be impeached, as ominous music played in the background.

Emily Cochrane and Luke Broadwater contributed reporting.