Biden remembered those who were killed and called for unity going forward.
Former President Donald Trump's historic second impeachment trial ended with a 57-43 vote to acquit in the Senate. He faced a single charge of incitement of insurrection over his actions leading up to the Jan. 6 riot at the U.S. Capitol.
Sens. Lindsey Graham, R-S.C. Ted Cruz, R-Texas, Kevin Cramer, R-N.D., and Roger Marshall, R-Kansas, asked Trump's defense whether a politician raising bail for rioters encourages more rioters.
"Does a politician raising bail for rioters encourage more rioting?" the Senate clerk read.
Bruce Castor, Jr of Trump's defense responded simply, "yes."
The first question in writing at Trump's second impeachment trial came from Senate Majority Leader Chuck Schumer and Sen. Dianne Feinstein, D-Calif., to the House impeachment managers.
"Is not the case that the violent attack and siege on the Capitol on Jan. 6 would not have happened if not for the conduct of President Trump," read presiding officer Sen. Patrick Leahy, D-Vt., president pro tempore of the Senate.
House impeachment manager Rep. Joaquin Castro, D-Texas, approached the lectern on behalf of the group.
"To answer your question very directly, Donald Trump summoned the mob. He assembled the mob and he lit the flame. Everything that followed was because of his doing. And although he could have immediately and forcefully intervened to stop the violence, he never did," Castro said. "In other words, this violent, bloody insurrection that occurred on Jan. 6 would not have occurred but for President Trump."
Castro emphasized their argument that the attack "did not happen by accident" and the "mob did not come out of thin air," citing Trump's repeated false claims of election fraud and calls to his supporters to "stop the steal."
He called the situation Trump created leading up to the Jan. 6 rally "incredibly combustible."
"He looked out the sea of thousands, some in body armor, with flagpoles, some of which beat Capitol Police with, and told them they could play by different rules," he said. "Once the attack began, insurgent after insurgent made clear they were following president orders."
The Senate has returned from a roughly 35-minute break following Trump's defense team wrapping up their arguments.
The trial is now in a question-and-answer portion, where senators can ask questions of the House managers and the Trump defense team. Questions are submitted in writing by senators and read aloud by presiding officer Sen. Patrick Leahy, D-Vt., president pro tempore of the Senate.
The question-and-answer portion of the trial is not to exceed four hours over one session day.
-ABC News' Trish Turner
A senior aide on the House impeachment managers' team told ABC News that the Trump team was given the trial record, including all video and audio used, prior to the start of the trial, despite the Trump defense team claiming otherwise.
Trump attorney David Shoen in earlier arguments Friday said his team was not given an opportunity to review House managers' evidence before the trial because they were not granted appropriate due process.
In addition to House managers saying all materials were given to Trump's defense team, Senate Minority Leader Mitch McConnell released at least two public statements in advance of Tuesday's trial saying due process was agreed to by both parties.
"Republicans set out to ensure the Senate's next steps will respect former President Trump's rights and due process, the institution of the Senate, and the office of the presidency. That goal has been achieved. This is a win for due process and fairness," McConnell said in a statement on Jan. 22. "This structure has been approved by both former President Trump's legal team and the House managers because it preserves due process and the rights of both sides," he said in another statement Monday.
Republican Sen. Lindsey Graham, a vocal ally of the former president, also tweeted this week that the trial resolution agreed upon is "fair to all concerned."
-ABC News' Trish Turner, Katherine Faulders and Benjamin Siegel
