Donald Trump "poured gasoline on the fire" during the riots at the US Capitol on 6 January 2021, a House investigation has heard.
And some of Mr Trump's closest advisers thought an attempt to overturn the 2020 US presidential election was "crazy", the select committee has also been told.
The latest session focused on an attempt to persuade Vice President Mike Pence to overturn the result and deny Joe Biden victory.
Conservative lawyer John Eastman came up with a plan to keep Mr Trump in the Oval Office.
The idea was to persuade Mr Pence to defy historical precedent when he presided over a joint session of Congress on the day of the riots and refuse to certify Mr Biden's win.
Mr Eastman argued that Mr Pence could reject results from certain states if he thought they were illegitimate, giving Republicans in those states an opportunity to declare Mr Trump the victor.
Mr Trump latched onto Mr Eastman's plan and started pressuring Mr Pence in public and in private.
Mr Trump tweeted at 2.24pm, while the attack on the Capitol was going on, that Mr Pence did not have the "courage" to stop the count.
"It felt like he was pouring gasoline on the fire by tweeting that," Sarah Matthews, a Trump White House staffer, said in a video statement.
Marc Short, Mike Pence's chief of staff, also gave evidence to the hearing, and said Mr Pence told Mr Trump "many times" that he did not have the authority to stop the vote being certified in Congress.
Gregory Jacob, a lawyer for Mr Pence, said Mr Eastman admitted in front of the president two days before the attack that his plan to have Mr Pence halt the procedure would violate the law.
"It is breathtaking that these arguments even were conceived, let alone entertained by the president of the United States," former US Appeals Court Judge J Michael Luttig, an informal Pence adviser, said.
Rioters outside the Capitol began shouting "hang Mike Pence" and came within 40ft of where he and his team were sheltering.
There was deep concern in the White House: Trump campaign adviser Jason Miller said those around Mr Trump were describing the plan as "crazy."
Eric Herschmann, a lawyer advising Mr Trump, said to Mr Eastman: "Are you out of your effing mind?"
In recorded testimony shown at the hearing, Mr Herschmann said he told Mr Eastman: "You're going to turn around and tell 78-plus million people in this country that your theory is this is how you're going to invalidate their votes?
"You're going to cause riots in the streets."
In the run-up to 6 January, Fox News's Sean Hannity texted Mr Trump's chief of staff, Mark Meadows, to say he was "very worried about the next 48 hours".
The committee's chairman, Democrat Bennie Thompson, said US democracy "came dangerously close to catastrophe".
There was "almost no idea more un-American" than the one Mr Pence was being asked to carry out - to reject the vote, Mr Thompson added.
By refusing Mr Trump's demands, Mr Pence "did his duty", said the panel's vice chair, Republican Liz Cheney.
Ahead of the hearing, Mr Short said his boss was determined to stay at the Capitol and finish the job.
"He knew his job was to stay at his post," Mr Short told CNN.
Mr Trump has repeatedly denied doing anything wrong, while continuing to claim he lost the election because of widespread fraud.