On January 6, when President Donald Trump’s supporters forced their way into the US Capitol building , killed a police officer and tried to stop the formal certification of the president’s re-election loss, one man stood among the Trump flags waving the banner of a different rebellion. The images of a Trump loyalist clutching a Confederate battle flag during an attack on the Capitol are likely to be among many from that day to define the Trump presidency after it ends at noon on Wednesday. But historians say the appearance of that flag – the emblem of a losing side in a civil war, more than a century and a half after it ended – is also a good reminder of something else: that Trump’s nascent legacy, even after four years as president, still has the potential to take on a powerful new life of its own in the years to come, long after he is gone. In particular, they warn that if the embers of disinformation about Trump’s re-election loss are not stamped out now – the fiction that Trump and his allies have been spreading to millions of his supporters, that he did not lose the election but had it stolen from him – they may come roaring back later with extraordinary power. “It is very dangerous because it can be used by demagogues and it has been used,” said the historian Margaret MacMillan, who has written extensively on World War I, in which Germany was defeated and surrendered, only to come surging back as a bitterly aggrieved nation under the Nazi flag. “The myth of the ‘stab in the back’ was quite a powerful one,” she said. “It was used by right-wing forces, including of course the Nazis, and these myths can have a great deal of mobilising power. But it takes people from the elite to actually support them as well.” Trump and his allies in Congress and the right-wing media have hammered the message to his supporters that the election was rigged, despite overwhelming evidence to the contrary, dozens of rejected lawsuits and a formal certification of the results by Vice-President Mike Pence not long after the violence ended at the Capitol. A CNBC analysis found that four of Trump’s 10 most popular tweets contained lies about the election. Republicans begin turning on Trump over impeachment Polls show the message got through. In a Reuters/Ipsos survey conducted before the Capitol attack, about 65 per cent of Republicans said they felt Biden’s election victory had come from illegal votes and election-rigging. After the attack, according to Reuters/Ipsos, Trump’s support within the Republican Party dropped to its all-time low – he was still backed by seven out of 10 Republicans surveyed. On January 6, a crowd of his supporters showed the nation they were willing to commit violence in Trump’s name, after he egged them on and told them: “You’ll never take back our country with weakness.” Later that evening, after the Capitol was cleared and Congress reconvened, Senator Josh Hawley, a Republican from Missouri, forced lawmakers to stay into the middle of the night so they could again debate whether to nullify the results in a swing state where Trump had lost. When Trump was impeached on January 13 for inciting an insurrection against the American government, 197 Republicans in the House voted to protect him. “Trump is nothing less than a religious figure to some of his most fanatical of followers,” said John Horgan, a Georgia State University psychology professor who studies deradicalisation. “I don’t think we have any real sense of just how profoundly damaging these events were.” “My concern is that the ‘big lie’ – that the election has been stolen – is already so entrenched that it will absolutely lay the foundation for the next generation of extreme right-wing militants in this country,” said Horgan, director of the university’s violent extremism research group. Angie Maxwell, director of the Diane Blair Centre of Southern Politics and Society at the University of Arkansas, said these myths have to be countered early and aggressively or else they can grow out of control with dangerous consequences. US lawmakers say two senators must resign for actions leading to siege After the American Civil War, she said, the alluring myth of the “lost cause” of the confederacy – another retelling of a lost war that ultimately led to more violence and bigotry – was given free rein to blossom in popular culture, history textbooks and US politics. “We didn’t stamp it out. We let those memorials stand. We let them have a modern meaning,” Maxwell said. “We let that energy continue, and that means those memorials and those flags and those sentiments can adapt over the generations, and mean something to people born decades and centuries after the original conflict,” she said. Trump did not acknowledge there would be a transition to a new administration until after his supporters assaulted the Capitol in his name. He still has not admitted that Joe Biden and Kamala Harris won the election, or that he was defeated, or that there was, in fact, no widespread fraud. Trumpism – however one wants to define it – can feed off of that resentment, according to the experts. “This is how the big lies become mythology, and mythologies become legend, and legends inspire people that find some connection with them,” Horgan said. “It has to be suffocated, that myth. But if you’re too afraid to do it, and you think it’ll just somehow fade into obscurity, that’s not what history teaches us. It has to be repudiated and it has to be snuffed out,” Maxwell said. “If they just pat him on the back and build his presidential library, history will repeat itself.” FBI tracking online chatter of armed protests ahead of Biden inauguration It remains unclear how many members of Trump’s Republican Party will break from him. During the House debate on impeachment on January 13, some of Trump’s defenders spent their time focusing on a different sort of legacy for the president – his policy legacy – while urging their colleagues not to punish him for inciting violence. “Let’s also be honest that this president did a lot to make America greater than ever,” Representative Lee Zeldin, a Republican from New York, said on the House floor. Whether some Trump policies – trade, climate change, the minimum wage, China – continue may be less a function of his cult of personality and more the general mood of the public and the pressure it puts on Congress. After Richard Nixon resigned the presidency in disgrace in 1974, Congress did not try to reverse all he had done. That included major policy changes like his pivotal decision to normalise relations with Beijing, said John Pomfret, author of The Beautiful Country and the Middle Kingdom , a history of US-China relations. “Generally speaking, the normalisation process went ahead – but just like then, today we have a situation where the only thing that Congress agrees about is support of Taiwan,” Pomfret said. “Both political parties, the only thing that they both agree on is a strong anti-China plank.” But lingering in the background of any policy debate is likely to be memories of the violence on January 6. Some of the people who have been arrested by the FBI carried plastic handcuffs and weapons with them into the Capitol, a sign they may have intended to kidnap or otherwise harm members of Congress during the attack. Now, experts say that for there to be a de-escalation of the growing tension, the distrust and lies, it will have to come at least in part from Trump’s own allies and the Republican Party itself. “As angry as people have a right to be about how far this went,” said Maxwell, the University of Arkansas historian, “you can’t make people feel criticised or dumb for having bought into it.” Department of Justice watchdog opens investigation into US Capitol riots After the attack, Cumulus Media, a company that owns right-wing radio stations across the country, ordered its on-air hosts to stop telling their millions of listeners that the election could still be overturned. Social media companies that Trump used to spread election disinformation for months have now kicked him off of their platforms for inciting violence. But when Trump called into a Republican National Committee call on the morning after the attack, he was reportedly greeted with cheers. “What has unquestionably complicated this, and made it worse several times over, has been the fact that he has been enabled and facilitated by senior figures in the Republican Party who have sustained him and have normalised and legitimised and sanitised him in a way that, if anything, they are going to be the targets if they stray from the course,” Horgan said. “It won’t be Trump.” Before the impeachment vote, Representative Jason Crow, a Democrat from Colorado, told MSNBC that a majority of his Republican colleagues were “paralysed with fear” about the consequences of turning on the president and voting against him. “My response was, not to be unsympathetic, but welcome to the club,” Crow said. “That’s leadership.” Ten Republicans voted to impeach Trump – the most bipartisan impeachment in American history. Among them was Representative Liz Cheney, the No 3 House Republican and daughter of former US vice-president Dick Cheney. She said Trump had “summoned this mob, assembled the mob and lit the flame of this attack”. In response, Representative Andy Biggs, the head of the House Freedom Caucus, a right-wing faction of House Republicans, told Fox News: “She’s not representing the Republican ideals.” US House votes to impeach Trump for inciting deadly Capitol insurrection Now the article of impeachment will go to the Senate, which will not only decide whether to convict Trump of inciting the insurrection, but also whether to ban him from ever holding office again. Mitch McConnell, the Senate Republican leader, has said he has not made up his mind on how he will vote. “I think a lot of the senior Republican elites have thought they could use Trump because he gets lots of support. And they become complicit,” MacMillan said. “That’s what happened in [Germany].” “I think what you have to do is find ways of breaking down those myths,” she added. “You look at the countries where there has been truth and reconciliation, it shows that it can be done. But it’s a long job, and it’s going to take a lot of work.”