CNN  — 

The House select committee probing the January 6 insurrection is signaling that it has penetrated Donald Trump’s wall of obstruction about what was going on inside the White House and his own family while he refused to stop the mob attack on the US Capitol a year ago this week.

Revelations delivered on Sunday by the top two lawmakers on the committee offer the clearest sign yet that it can get to the truth about the violence Trump incited to further his coup attempt, which turned into the worst assault on American democracy in modern times. And a person familiar with the inquiry told CNN’s Jamie Gangel that one of the key witnesses who has given testimony is Keith Kellogg, former Vice President Mike Pence’s national security adviser, who was with Trump in the White House as the riot raged.

Committee chairman Bennie Thompson, a Democrat from Mississippi, said on CNN’s “State of the Union” that the panel has “significant testimony” that shows the White House was told to “do something” as the crowd of Trump supporters fired up by his election fantasies smashed their way into the Capitol. Vice Chair Liz Cheney, a Wyoming Republican, told ABC News of “firsthand testimony” that Trump’s daughter Ivanka, then a West Wing adviser, twice asked him to intervene in a melee in which police officers were beaten by his crowd.

The source also told CNN’s Gangel that the committee has texts and other documents that show what the President was doing and not doing at the time, including some from former White House chief of staff Mark Meadows. The new details about there being first-hand information from inside the West Wing serve as a warning to Trump that his relentless efforts to hide the truth about a day that will live in infamy may not work. And it may deter other witnesses from holding out against the committee.

Thursday’s anniversary will revisit the horrors of the attack, before which Trump had told his supporters to “fight like hell” in support of his conspiracy to steal power from Joe Biden in violation of the will of the people expressed in a democratic election.

And now the comments from committee leadership shed fresh light on the motivation behind the ex-President’s quest to keep secret documentary evidence of his role on January 6, which has reached all the way to the US Supreme Court. They also explain the refusal of several of Trump’s closest aides and acolytes to talk to the committee about what exactly he was doing in the Oval Office. It is increasingly clear that those appearances might force them to choose between telling the truth under oath and crossing their old boss, who still dominates the GOP. Two such Trump allies – Meadows and his former political guru Steve Bannon – have already received criminal contempt referrals to the Justice Department from the committee and the full House. Bannon faces trial in July. Meadows has provided documentary evidence to the committee but has halted cooperation.

But this week’s events will also underscore that a year on, Trump’s enormous power over the GOP and the complicity of many of its top leaders in his voting fraud lies means that US democracy is in deeper trouble and under broader assault than ever.

A widening picture of dereliction of duty

Thompson’s and Cheney’s comments will also fuel a growing impression that the committee, which has conducted several hundred interviews, has built a detailed behind-the-scenes picture of what went on inside Trump’s West Wing on an infamous day in US history. Some of that evidence has already emerged in journalistic accounts of what went on during the insurrection. But the committee’s eventual final report would have the capacity to create a definitive record for history – and for future voters – on the truth about the attack.

There were additional signs on Sunday that the committee is making inroads into tracing the funding of the rally at the Ellipse in Washington, DC, that Trump addressed with his inflammatory lies about election fraud on January 6. Thompson raised concerns on “State of the Union” about the possibility of financial fraud in relation to the event.

“We have not made those concerns public at this point. But we do think it’s highly concerning on our part that people raised monies for one activity, and we can’t find the money being spent for that particular activity,” he said.

The chairman also notably refused to rule out the notion that the committee could take the extraordinary step of making a criminal referral of Trump to the Justice Department. While it is not clear if the full committee would be on board for such a move, it would raise the prospect of the attorney general of one administration considering an indictment of the President from the previous White House, a conundrum that could pour more fuel on a raging political inferno in a midterm election year.

“We don’t know … If there’s anything we come upon as a committee that we think would warrant a referral to the Department of Justice, we’ll do that,” Thompson told Dana Bash. Cheney added on CBS that Trump was guilty of a “supreme dereliction of duty” and that the committee was looking at whether there was a need for “enhanced penalties” for such behavior, though she appeared to be referring to legislation that would not likely be retrospective in relation to Trump’s conduct.

‘Unfit for office’

Cheney did, however, warn that Trump’s conduct was so egregious that he should not be allowed anywhere near power again, as the former President considers a potential new tilt at the White House in 2024.

“This is a man who has demonstrated that he’s at war with the rule of law. He’s demonstrated that he’s willing to blow through every guardrail of democracy,” Cheney said on CBS News’ “Face the Nation” on Sunday. “And he can never be anywhere near the Oval Office again.”

On the face of it, a refusal by the commander in chief to intervene to stop an assault on the citadel of American democracy during the process of certifying Biden’s election is a clear infringement of his oath of office to preserve, protect and defend the Constitution.

But even a deeply damning report by the committee would seem unlikely to break the dynamic of denial in the GOP over Trump’s transgressions.

A new poll, for example, from the Washington Post and the University of Maryland shows that only 27% of Republicans believe that the former President deserves “a great deal” or “good amount” of blame for the attack on the Capitol on January 6.

Such data, which reflects a year of lies by Trump and conservative media, helps explain why the House GOP especially has anchored its hopes of capturing a majority in the midterm elections on fealty to the insurrectionist ex-President. Apart from Cheney and the other Republican on the select committee, Illinois Rep. Adam Kinzinger, much of the Republican conference is participating in or abetting the whitewashing of history.

Trump has already announced he will give fresh impetus to a process that has convinced millions of grassroots supporters of the lie that he was cheated out of power and should still be president, with a press conference at his luxury Mar-a-Lago club in Florida on Thursday. The ex-President plans to argue that the real insurrection took place during the November 2020 election – which Biden won in a free and fair vote — not on January 6, even though the attack on the Capitol took place in front of the eyes of the world and there’s no evidence of election fraud in 2020.

‘We want to verify all of it’

The committee is bearing down on what it says are the crucial 187 minutes between the start of the Capitol insurrection and Trump issuing a message to supporters to go home. Thompson hinted there are signs that the ex-President tried to tape several previous messages but his words did not apparently sufficiently meet the moment and were not released by the White House. That is one reason why the committee wants the Supreme Court to allow it to examine documents, texts, emails and memos over which Biden has declined to assert executive privilege but which Trump does not want to be handed over. After several previous reversals in court, the ex-President in the days before Christmas appealed to the conservative majority on the Supreme Court that he helped build.

“We have significant testimony that leads us to believe that the White House had been told to do something,” Thompson told Bash Sunday. “We want to verify all of it, so that, when we produce our report and when we have the hearings, the public will have an opportunity to see for themselves.”

The chairman added: “The only thing I can say, it’s highly unusual for anyone in charge of anything to watch what’s going on and do nothing.”

Cheney also weighed in on those crucial moments, fleshing out reporting contained in the books “I Alone Can Fix It” by Washington Post reporters Carol Leonnig and Philip Rucker and “Peril” by Post journalists Bob Woodward and Robert Costa.

“We know his daughter – we have firsthand testimony that his daughter Ivanka went in at least twice to ask him to ‘please stop this violence,’” Cheney told ABC News’ “This Week.”

Cheney’s willingness to pursue the truth of January 6, which sets her apart from many of her fellow House Republicans, has seen her ostracized by her party. She lost a leadership post in the House Republican conference and is being challenged by a Trump-backed primary challenger. But she still expressed hope on CBS on Sunday that a committee trashed by Trump’s allies on Capitol Hill could produce evidence with the power to change the minds of skeptics. She also had a challenge for her party, much of which long ago chose to shield Trump and disregard the truth for political gain.

“Our party has to choose. We can either be loyal to Donald Trump or we can be loyal to the Constitution, but we cannot be both,” she said.

This story has been updated with additional developments Monday.

CNN’s Jamie Gangel contributed to this report.