Cheney, the panel's vice chair, said Trump "deceived" his supporters by touting unfounded claims of widespread voter fraud.

"No rational or sane man in his position could disregard that information and reach the opposite conclusion." Reading from a teleprompter, Cheney also indicated that the committee would show evidence that Trump's circle of advisers knew they lacked evidence to support claims of widespread fraud.

"As you watch our hearing today, I would urge you to keep your eye on two specific points. First, you will see evidence that Trump's legal team, led by Rudy Giuliani, knew that they lacked actual evidence of widespread fraud to prove that the election was actually stolen. They knew it, but they went ahead with Jan. 6 anyway," she added. "And second, consider how millions of Americans were persuaded to believe what Donald Trump's closes advisers in his administration did not."

"These Americans did not have access to the truth like Donald Trump did. They put their faith and their trust in Donald Trump. They wanted to believe in him. They wanted to fight for their country, and he deceived them. For millions of Americans, that may be painful to accept, but it is true," Cheney concluded.

Vice Chair Liz Cheney, R-Wyo, said Trump allies are taking a new strategy in an attempt to discredit the committee's hearings after initially denying its findings.

"Now the argument seems to be that President Trump was manipulated by others outside the administration," Cheney said. She noted that fingers are being pointed at Trump advisers such as John Eastman or Sydney Powell, or Rep. Scott Perry.

"This, of course, is nonsense," Cheney continued. "President Trump is a 76-year-old man. He is not an impressionable child."

Cheney said the committee has shown Trump had access to more detailed and specific information showing that the election was not actually stolen than almost anyone else in the nation.

"No rational or sane man in his position could disregard that information and reach the opposite conclusion," she argued. "Donald Trump cannot escape responsibility by being willfully blind."

Committee Chair Bennie Thompson gaveled in the hearing shortly after 1 p.m. and immediately invoked a core theme the committee has emphasized in its public hearings.

"We settle our differences at the ballot box," he said, before raising how Trump handled his election loss.

"He seized on the anger of his supporters, and when they approached the line, he didn't wave them off, he urged them on," Thompson said.

"Today, the committee will explain how, as a part of the last-ditch effort to overturn the election and block the transfer of power, Donald Trump summoned a mob to Washington D.C. -- and ultimately, spurred that mob to wage a violent attack on our democracy," he said.

Capitol Police officer Harry Dunn, who testified at the first select committee hearing last fall on how he feared for his life and faced racist attacks while defending the Capitol on Jan. 6, told ABC News Congressional Correspondent Rachel Scott ahead of the hearing today that he's expecting the afternoon to be "triggering" -- and that he is "emotionally, preparing for the worst."

With Jan. 6 defendant Stephen Ayres set to testify, Dunn said Ayres "owes everyone in the congressional community who was affected by the day an apology." Adding, "if he stops short of being honest about the violence -- that doesn't do enough for me. If he stops short of apologizing -- that doesn't do enough for me."

Metropolitan Police Department officer Daniel Hodges, who also defended the Capitol and has also been a regular fixture at the public hearings, said it will be notable for Americans to hear what happened straight from someone who breached the building, given that some continue to downplay the violence.

"Having one of the people involved in the attack on Capitol -- in their own words describe their mentality, their intentions and the intentions of the group -- you can't get any closer to the source than that."