Whether it was praising white supremacists, siding with Vladimir Putin or suggesting bleach as a coronavirus cure, there was nothing that Donald Trump could do to make the Republican party fall out of love with him.

Then came 6 January, and – for a brief moment – it seemed that was no longer true.

“Today all I can say is: count me out,” said Lindsey Graham, standing in a Senate chamber that just hours earlier had been overrun by a pro-Trump mob determined to overturn the 2020 presidential election. “Enough is enough.”

A week later he was joined by Kevin McCarthy, the Republican minority leader in the House of Representatives, who called on Trump to “accept his share of responsibility” for the deadly violence at the Capitol. Other allies turned against the president. If ever there was a moment that the party could snap out of its five-year fever dream, this was it. Yet it did not.

In the year since the insurrection that reverberated around the world, Trump’s stranglehold on Republicans has seemingly become stronger, not weaker. Graham was soon back on the golf course with him; McCarthy was soon kissing the ring at his Mar-a-Lago estate in Florida. Many leaders of the party have set about changing the narrative of the insurrection to portray it as a heroic last stand – a new “lost cause”.

“We now have a major political party that is embracing violence systematically,” said Elaine Kamarck, a senior fellow at the Brookings Institution thinktank in Washington and former White House official. “They’re rewriting the events of January 6. They’re referring, as President Trump does, to these people as patriots. They are stirring up a minority.”

Trump was the first president in American history to inspire an attempted coup. After a rally where the defeated incumbent urged supporters to “fight like hell”, the angry mob laid siege to the US Capitol to disrupt the certification of Joe Biden’s victory.

Five people died, scores of police were beaten and bloodied and there was about $1.5m in damage in the first major attack on the Capitol since the war of 1812. More than 700 people have been charged in one of the biggest criminal investigations in American history.

But even on the night 6 January, as members of the House and Senate stepped over blood and broken glass to get the job, some 147 Republicans still voted to overturn the election results. It was the first clue that Trump had burrowed too far down into the party’s foundations to be expunged – and that anyone who tried would themselves be purged.

The second clue came after Trump had been impeached – for the second time – by the House, a vote in which just 10 Republicans joined Democrats. A majority of senators voted to convict the former president but fell 10 votes short of the two-thirds majority required by the constitution. Trump was acquitted.

Jamie Raskin, a Democratic congressman who was the lead impeachment manager, said: “The evidence was so overwhelming, our legal case was so airtight and Trump’s culpability was so plain to see, I thought that perhaps the Republican party would use this as an opportunity to perform an exorcism on their own body.

“But Trump just controls way too much money and too much power in the Republican party and it was really only a matter of a week or two before he reasserted his authoritarian, cult-like control over the whole GOP [Grand Old Party] apparatus.”

The third clue, demonstrating Raskin’s point, came in May when Senate Republicans voted down an independent commission to investigate the riot, based on the model of a commission that examined the September 11, 2001 terrorist attacks. Even the minority leader, Mitch McConnell, who had condemned Trump for inciting the violence and remains an arch foe, dismissed the proposed commission as a “purely political exercise”.

Democrats instead created a House select committee to examine the events of that day and understand what role Trump played. It has interviewed hundreds of people and is threatening jail time for those who refuse to comply. But it has only two Republican members, Liz Cheney and Adam Kinzinger, and their fates say much about the direction of the party.

Cheney, vice-chair of the committee and daughter of the former vice-president Dick Cheney, has faced the wrath of the Republican party of Wyoming, which voted to no longer recognise her as a Republican. She will be challenged for her seat in a primary election by a pro-Trump candidate. Kinzinger has been subjected to death threats and will not seek reelection.

Michael Steele, former chairman of the Republican National Committee, said: “They have to rewrite the history because that’s the only way they can justify their existence because if you let the actual facts of history speak to the truth of who they are, then I don’t know how they look themselves in the face in the morning.”

Today the loudest voices in the Republican party belong to the extremists. For them, Trump’s “big lie” that the election was stolen from him due to voter fraud, rendering Biden an illegitimate president, goes hand in hand with the lie that the insurrection was a morally justified crusade, an righteous endeavor to save democracy, not destroy it.

Trump himself perpetuates this through a regular barrage of interviews, rallies and emailed statements since he was barred from Twitter. Notably he has sought to lionize Ashli Babbitt, who was shot dead during the riot, as a martyr.

Marjorie Taylor Greene, a Republican congresswoman, has cast rioters currently held in detention in a similar light. In November she visit a Washington jail’s so-called “patriot wing” and complained the inmates were enduring “inhumane” conditions because of their political beliefs.

Other pro-Trump Republicans in the House echo these messages – one referred to the Capitol attack as a “normal tourist visit” – or do little to contradict them. Some Republican senators are evidently more uncomfortable with the web of deceit and urge the party to look forward to the next election. But again only a small minority are willing to take Trump on directly.

All are aware of the power of rightwing media over state Republican parties and the “Make America great again” base. Fox News host Tucker Carlson produced a three-part documentary, Patriot Purge, for the Fox Nation streaming platform that pushed the bogus claim that the insurrection was a “false flag” operation designed to hurt Trump’s supporters.

Steve Bannon, a former adviser to Trump, uses his “War Room” podcast to promote the “big lie” that Trump won re-election in a landslide and features guests such as Mike Lindell, a pillow businessman who peddles wild conspiracy theories. Bannon encourages listeners to support the legal defence of the 6 January “political prisoners”.

This has helped fuel a climate in which fealty to Trump and his debunked narrative is a litmus test for Republican candidates for Congress. Almost a third of Republicans believe violence may be necessary to “save” the US, according to a recent poll by the Public Religion Research Institute.

Trump’s resilient ability to bend the party to his will, and to his disinformation about election “integrity”, have fueled a drive to make it harder to vote, likely to have a disproportionate impact on Democrats. Between January and October, 19 states enacted 33 laws to restrict voting access, according to the Brennan Center for Justice.

In addition, Trump loyalists are running as candidates for secretaries of state and other positions that would give them power over the running of future elections. With Republicans in a strong position to regain control of the House and Senate this year, the party is readying for a repeat of 6 January with a different outcome.

Steele added: “The elements of it are being played out in states throughout the country as Republicans rewrite the election laws in their favor.”

One year on, many analysts argue that America is now split between a Democratic party and anti-democratic party, the latter being barely recognisable as the one-time home of Abraham Lincoln and Dwight Eisenhower. Instead Trump remains its most powerful and popular figure and could run for the White House again in 2024.

Kurt Bardella, an adviser to the Democratic National Committee, believes that 6 January will go down as the day that the Republican party surrendered to “an anti-democratic terrorist cell” and that its mission since has been to permanently undermine democracy.

“I have long said that January 6 was merely a dress rehearsal for how Republicans intend to try to hijack free and fair democratic elections in this country going forward,” added Bardella, a former Republican congressional aide.

“They know that when the playing field is level and everybody can participate in the democratic process, they cannot win, so the only recourse that they believe that they can obtain power is by throwing out democratic norms and overthrowing elections, even if that means using instruments of violence, fear and terror to do so.”