The House committee investigating the January 6 insurrection charged on Monday that Donald Trump “lit the fuse” that fueled the most violent assault on the US Capitol in more than two centuries with his groundless claim that the election was stolen.

For those tuned in, the committee meticulously charted the origins and spread of Trump’s “big lie”, tapping a trove of evidence and interviews to show that the former president was told repeatedly that the election had been free and fair and peddled his myths anyway.

But in Republican politics and the conservative media ecosystem, Trump’s myth of a stolen election rages on, uncontrolled in the Republican party as it seeks to surge back into power in November’s midterm elections.

Roughly two-thirds of Republicans believe fraud helped Joe Biden win, according to a Reuters/Ipsos poll released ahead of the first hearing last week. Across the country, Republican election deniers are running for office and the lie is being used as the basis to pass scores of pieces of legislation restricting voting access.

The January 6 panel is doing its best to counter that narrative. In a methodical presentation on Monday, the panel charted how the defeated former president kindled false claims of voter fraud as part of a conspiracy to remain in power against the electoral will of the American people.

“This morning, we’ll tell the story of how Donald Trump lost an election, and knew he lost an election – and as a result of his loss decided to wage an attack on our democracy,” Congressman Bennie Thompson, chair of the committee and a Democrat from Mississippi, said opening Monday’s hearing.

The violence on 6 January, when a mob of loyalist to the president overran the Capitol in an attempt to stop Congress from certifying Biden’s victory, was a “direct and predictable result” of lies Trump told, Thompson said.

During the hearing, the committee turned to the former president’s inner circle to argue that Trump, defeated and desperate, continued to push baseless claims about election fraud that he had been told repeatedly were false.

“He’s become detached from reality if he really believes this stuff,” Bill Bar, the former attorney general, testified to the panel in a clip played during the hearing. “There was never an indication of interest in what the actual facts were,” he added. At one point during the deposition, Barr laughs at the sheer absurdity of the claims, one of which involved a plot orchestrated by the former Venezuelan leader, Hugo Chávez. Chávez died in 2013.

Barr said he told the president the claims of fraud were “bullshit”.

Trump’s former campaign manager, Bill Stepien, testified to the committee that he knew their path to victory had all-but evaporated and sought to dissuade the then president from declaring victory prematurely. But Trump ignored his pleas for caution and instead heeded the advice of an “apparently inebriated” Rudy Giuliani to claim he won an election when it was increasingly clear he had not.

Stepien was expected to appear in person on Monday, but abruptly pulled out because his wife went into labor. The ex-campaign manager, who remains close to Trump, had reportedly been subpoenaed to appear. The committee instead played extended clips from his recorded testimony.

In the days that followed, Stepien said two factions developed within the campaign, his team and another led by Giuliani. His team, he said, became known as ‘Team Normal’”.

The committee also alleged that Trump had duped his supporters into sending money so that his campaign could keep fighting to overturn the results in court. Some members on the panel have suggested that the revelation Trump misled his donors could perhaps shake their yet-unshakable fealty to the defeated president.

“The big lie was also a big rip-off,” said Congresswoman Zoe Lofgren, a Democrat of California, who led the panel’s presentation on Monday.

Breaking Trump’s hold on his supporters and the Republican party may be too tall a task for the committee. Even as Stepien helped the committee – and the country – better understand the tumultuous aftermath of the 2020 election, he is working to bring down the panel’s vice-chair, congresswoman Liz Cheney.

Stepien serves as an adviser to Harriet Hageman, a Wyoming Republican running a Trump-fueled primary challenge against Cheney. The former president has made defeating Cheney a priority as part of a revenge-campaign against Republicans who defied his efforts to overturn the election results. Cheney’s unflinching pursuit of Trump has made her a pariah in her party – and may yet cost her her political career.

Throughout the hearing, the committee sought to disprove Trump’s fictions, in some instances, claim by claim.

“Dead people are voting. Indians are getting paid to vote. There’s lots of fraud going on here,” former acting attorney general Richard Donoghue said, recalling the litany of outlandish claims Trump made to him. Donoghue said he told Trump “flat out that much of the information he’s getting is false and/or is not supported by the evidence”.

“There were so many of these allegations that when you gave him a very direct answer on one of them, he wouldn’t fight us on it, but he’d move to another allegation,” he said.

In another recorded interview with the panel, Eric Herschmann, a White House lawyer, recalled a phone call with John Eastman, one of the president’s lawyers whom a judge has said conspired with Trump to overturn the election.

“I said to him, Are you out of your effing mind?” Herschmann recalled. “I said I… only want to hear two words coming out of your mouth for now on: orderly transition.”

Among the witnesses on Monday was Chris Stirewalt, a former Fox News Channel political editor who declared on election night that Biden had won Arizona, once a Republican stronghold.

Stirewalt told the panel that Trump had no reasonable basis for declaring victory on election night, as the former president did. To win, Trump would have needed the tally in three states to dramatically shift in his favor, the former news editor explained, an outcome so unlikely “you’re better off to play the Powerball”.

Presently, the odds of winning the Powerball jackpot are about1 in 292,201,338.

Asked who won the 2020 election, Stirewalt replied with the gusto of a broadcaster on election night: “Joseph Robinette Biden, Jr of the great state of Delaware.”

“That’s the bottom line,” Thompson replied.

But for many, it is not. Across the US, Republicans are running for office fueling the myth of a stolen election and they are likely to pay little heed to the facts and evidence gathered by the committee.

In Pennsylvania, Doug Mastriano, who was a leader in efforts to overturn the 2020 election in the state and put Trump’s election lies at the heart of his campaign, won the Republican primary for governor. The committee subpoenaed Mastriano over his involvement in planning and organizing the January 6 rally that preceded the Capitol assault.

If elected, he would have extraordinary control over the election administration in a critical swing state. On Monday, as the hearing was getting underway in Washington, Mastriano’s campaign announced that it had brought on former Trump campaign lawyer Jenna Ellis, who became the public face of his brazen legal efforts to overturn the presidential elections.

In a statement, Ellis vowed – apparently without irony – to help Mastriano “restore integrity to our elections”.