Democrats on Wednesday will show new security camera video depicting the deadly attack on the US Capitol by Donald Trump's supporters as they open their formal case charging the former president with inciting insurrection.
Senior aides to the House of Representatives managers prosecuting the case said they will also argue that Trump's false claims of fraud in November's election laid the ground for the Jan. 6 assault.
The House has charged Trump, a Republican, with inciting an insurrection by exhorting thousands of supporters to march on the Capitol, where Congress was gathered to certify Democrat Joe Biden's electoral victory.
Democrats played dramatic video of the Capitol attack on the first day of the trial in the Senate on Tuesday and planned to show more on Wednesday.
"We will be using footage never seen before that shows a view of the Capitol that is quite extraordinary and a view of the attack that has never been public before," one senior aide said.
In an assault that stunned the world, the rioters stormed the Capitol in a futile effort to stop Biden's win, sending lawmakers into hiding and leaving five people dead, including a police officer.
Trump made multiple false assertions that he lost the election only because of widespread fraud.
"You're going to hear the provocation. You are going to hear how Trump inflamed his base leading up to it with his lies about the election being stolen; how they have to 'stop the steal.' He wanted a landslide," the senior aide said in a briefing before the trial resumes at noon EST (1700 GMT).
"Jan. 6 was the culmination of his conduct not a beginning of it."
On Tuesday, the Senate voted that the impeachment trial could move ahead even though Trump's term ended on Jan. 20. Six out of 50 Republican senators broke with their caucus to side with Democrats.
Tuesday's split vote suggests Democrats face long odds in securing a conviction and barring Trump from seeking public office again. A two-thirds majority in the Senate must vote to convict, which means at least 17 Republicans would have to defy Trump's still-potent popularity among Republican voters.
Nine Democratic House members acting as Trump's prosecutors on Tuesday accused Trump of encouraging his backers to block the peaceful transfer of power, a hallmark of American democracy.
"If that's not an impeachable offense, then there's no such thing," said US Representative Jamie Raskin, who delivered an emotional speech recounting how he became separated from his daughter and son-in-law during the violence.
Trump's lawyers argued that the former president's rhetoric is protected by the First Amendment's guarantee of free speech and that the individuals who breached the Capitol, not Trump, were responsible for their own criminal behavior.
The lawyers sought to portray the trial as a sham aimed at ending Trump's political career while ignoring basic principles of fairness and due process.
"We are really here because the majority in the House of Representatives does not want to face Donald Trump as a political rival in the future," Bruce Castor, one of Trump's lawyers, told senators.
The Democratic-led House impeached Trump one week after the riot, making him the first US president to be impeached twice.
Trump's first impeachment trial, which stemmed from his efforts to pressure Ukraine to investigate Biden during the presidential campaign, ended in an acquittal a year ago in what was then a Republican-controlled Senate.
Party leaders have agreed on a fast-moving schedule that could lead to a vote on conviction or acquittal by early next week. Some Democrats had expressed concern that a prolonged trial could delay progress on Biden's agenda, including a proposed $1.9 trillion coronavirus relief package.
Biden was not planning to watch the trial, the White House said, and spent Tuesday meeting business leaders in the Oval Office. Asked about the proceedings, the president said he was focused on his own job.
"The Senate has their job; they're about to begin it. I'm sure they're going to conduct themselves well," he said.
No US president has ever been removed from office via impeachment. Bill Clinton was impeached in 1998 and Andrew Johnson in 1868 but they also were acquitted. Richard Nixon resigned in 1974 rather than face impeachment over the Watergate scandal.