Jan. 6 hearing shows Barr saying Trump 'detached from reality' in pushing 'big lie'

"It was far too early to be making any calls like that," Trump's former campaign manager Bill Stepien told the committee in his video deposition. "Ballots were still being counted, ballots were still going to be counted for days."

Ivanka Trump also told the committee that it was becoming clear the race would not be called that night.

"To the best of my memory, I was saying that we should not go with declare victory until we had a better sense of the numbers," former top Trump aide Jason Miller said in his videotaped interview.

Stepien and Miller said it was former New York City mayor Rudy Giuliani who pressured Trump to claim victory. Miller alleged that Giuliani was "definitely intoxicated" at the time, which Giuliani's attorney, Bob Costello, subsequently denied in a statement to ABC News: "He didn’t drink alcohol that evening, only Diet Coke. He doesn’t know why Jason Miller would make that false claim."

The committee aired a snippet of Trump's speech on election night, in which he told the crowd: "We were getting ready to win this election. Frankly, we did win this."

ABC News' John Santucci contributed to this report.

Rep. Zoe Lofgren, D-Calif., said the committee will demonstrate that Trump and his closest advisers knew his claims of election fraud were false, but continued to peddle them anyway, and even fundraised off those claims which "rioters later used to justify attacking the Capitol on Jan. 6."

"We will also show that the Trump campaign used these false claims of election fraud to raise hundreds of millions of dollars from supporters who were told the donations were for the legal fight in the courts. But the Trump campaign didn't use the money for that," she said.

"'The big lie' was also a big ripoff," Lofgren added, going on to use video of Trump to argue that he "laid the groundwork for these false claims well in advance of the election."

Using video testimony, Vice Chair Liz Cheney said the committee will show how Trump and his campaign knew the election was lost but continued to espouse the "big lie," laying out three points to focus on.

"First, you will hear firsthand testimony that the president's campaign advisers urged him to await the counting of votes and not to declare victory on election night. The president understood, even before the election, that many more Biden voters had voted by mail because President Trump ignored the advice of his campaign experts and told his supporters only to vote in person," she said, attempting to illustrate Trump was aware.

"Second, pay attention to what Donald Trump and his legal team said repeatedly about Dominion voting machines," Cheney said, calling them "Far-flung conspiracies with deceased Venezuelan communists allegedly pulling the strings," which even Trump Attorney General Bill Barr and White House lawyer Eric Herschmann didn't believe.

"And third, as Mike Pence's staff started to get a sense for what Donald Trump had planned for January 6, they called the campaign experts to give them a briefing on election fraud and all the other election claims," she said. "On January 2nd, the general counsel of the Trump campaign, Matthew Morgan -- this is a campaign's chief lawyer -- summarized what the campaign had concluded weeks earlier, that none of the arguments about fraud or anything else could actually change the outcome of the election."

Committee Vice Chair Rep. Liz Cheney, R-Wyo., shared deposition testimony from former White House lawyer Eric Herschmann on the former president's baseless claims that Dominion voting machines were compromised.

"I never saw any evidence whatsoever to sustain those allegations," Herschmann told the committee.

Cheney claimed that Herschmann's view was shared by many in the Trump team that the committee interviewed .

Dominion has filed several defamation lawsuits against those who spread baseless claims that their voting machines "stole" votes.