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

Inside the Senate's first impeachment trial of a former president -- and the first during a global pandemic -- a pool of reporters were permitted to cycle inside, one at a time to witness the floor activity not necessarily captured by cameras stationed there.

ABC News' Trish Turner noted that every senator was in the chamber for the start. Republicans could be seen handing in their electronics as they entered the chamber though the GOP cloakroom as phones are not allowed during the trial. 

At the Trump legal team desk, closest to the lectern, sat Trump's four attorneys: David Schoen, Bruce Castor, Michael van der Veen and Julieanne Bateman, along with a legal aide. At the House managers table sat Rep. Jamie Raskin, D-Md., with counsel Barry Berke and a legal aide. 

Schoen and Sen. Patrick Leahy, D-Vt., the president pro tempore presiding over the trial, made small talk before the trial started. 

All senators were masked up but a handful including Sen. Cynthia Lummis, R-Wyo., Sen. James Risch, R-Wis., and Sen. Rand Paul, R-Ky.

Van der veen was the only lawyer at the Trump table reading and marking up documents. The others each sat with a blank, yellow legal pad. 

When asked if they were an opponent or proponent of the constitutional question, Raskin and then Castor said, "We're a proponent" and "We're an opponent," respectively. 

Another reporter from the pool described the atmosphere in the chamber as "incredibly tense" while senators watched the video compilation from Raskin of the assault on the Capitol. 

Almost every senator was watching the video, most wearing frowns, the reporter noted, and the sounds of the video appeared to echo in the chamber, "filling it with the screams and yells of the mob."

-ABC News' Trish Turner

Rep. Jamie Raskin, D-Md., argued for the historical precedent of impeachment, arguing that the Framers had impeachment of a person no longer in office in mind when drafting the Constitution.

"President Trump may not know a lot about the Framers, but they certainly knew a lot about him," Raskin said. "Given the Framers' intense focus on danger to elections and the peaceful transfer of power, it is inconceivable that they designed impeachment to be a dead letter in the president's final days in office when opportunities to interfere with the peaceful transfer of power would be most tempting and most dangerous, as we just saw."

Senators gathered on Tuesday for the historic second impeachment of Trump, the first trial of a former a president and one in which the lawmakers are themselves witnesses to the insurrection at the Capitol.

Here are photos of the Jan. 6 attack on the Capitol.

Rep. Jamie Raskin, D-Md., tapped by House Speaker Nancy Pelosi to serve as the lead House impeachment manager, opened arguments at Tuesday's trial, laying out the constitutionality of the Senate trial.

"You will not hear a lecture here because our case is based on cold, hard facts. It's all about the facts," Raskin said, before warning of the "dangerous" precedent it would set, if the Senate allowed a president to "get away with" committing an impeachable offense in the last few weeks of office, as he argues Trump did.

"This would create a brand new January exception to the Constitution of the United States of America. A January exception. And everyone can see immediately why this is so dangerous. It's 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 onto the Oval Office at all costs, and to block the peaceful transfer of power," Raskin said.

"In other words, the January exception is an invitation to our Founders' worst nightmare. And if we buy this radical argument that President Trump's lawyers advance, we risk having Jan. 6 become our future. What will that mean for America? Think about it. What will the January exception mean to future generations if you grant it?" Raskin asked.

"I'll show you," he said, before playing a roughly 10-minute long video of inter-spliced footage of the Capitol attack, Trump's speech leading up to it and aftermath.

Raskin, a Harvard-educated, former constitutional law professor serving in his third term in the House, was the lead author of the impeachment article and began writing it from inside the Capitol on Jan. 6.