It’s understandable if you thought the threat had gone. Donald Trump left office nearly a year ago, is no longer serving up daily outrages by tweet, and is reduced to appearing with Nigel Farage on GB News. But the menace he represented lingers, and not only because Trump remains the most likely Republican presidential nominee for 2024, a contest he could well win given the parlous approval ratings of the current incumbent. Trumpism lives on in the legacy he left behind, its most visible incarnation perhaps the three ultra-conservative judges he selected for the supreme court, who this week began hearing a case on abortion – one that many expect to result in the removal of American women’s constitutionally protected right to end an unwanted pregnancy. But Trumpism endures too in the party he remade in his own image. He has left behind a Republican party no longer committed to democracy. That sounds hyperbolic but, if anything, it understates the case. Republicans are breaking from the principle that precedes the idea of democracy and is even more fundamental: the belief that arguments between citizens should be resolved by peaceful means. Today’s Republican party is normalising the notion of violence as a means of securing a political outcome. Start with the case of Paul Gosar, the Republican member of Congress for Arizona. He retweeted an anime-style video that depicted him murdering his Democratic colleague, Alexandria Ocasio-Cortez, as well as swinging a sword at Joe Biden. Appalling though that was, especially at a time when AOC and others face constant threats of violence, more telling was the response of Gosar’s party. When Democrats moved to censure him, only two Republicans voted with them. The 200-odd others gave Gosar their blessing. Earlier, Republicans had had to make a similar decision. Before her election to Congress in 2020, Marjorie Taylor Greene had posted on Facebook a photograph of herself holding a gun next to an image of AOC and two other members of the so-called Squad, made up of left-leaning Democratic women of colour. Taylor Greene also all but called for the execution of the House speaker, Nancy Pelosi. Yet when Democrats voted to kick the Georgia Republican off the various congressional committees she sat on, only 11 members of her party voted with them. The rest stood with her. Of course, the pattern was set with the Republican response to Trump himself, and his encouragement of the attempt to overturn a democratic election by force earlier this year. Republicans could have repudiated the storming of the Capitol on 6 January by joining their Democratic colleagues in voting to impeach the outgoing president for “inciting an insurrection”. But only 10 Republicans did so. Since then, those 10 dissenters have been pilloried and ostracised by their fellow Republicans. Among the shunned is Liz Cheney, who was stripped of her House leadership role and expelled from the state Republican party in her native Wyoming. She’s an arch-conservative like her former vice-president father, but that didn’t matter. Cheney believes in respecting elections – and that was enough to put her beyond the pale. These responses – coddling the advocates of violence, punishing those who denounce it – prove the truth of the declaration that Taylor Greene made this week: “We are not the fringe. We are the base of the party.” She’s right. She and Gosar are in lockstep with a Republican party whose face can be seen in the death threats now routinely meted out not only to nationally famous politicians such as AOC, but to the officials and volunteers who serve in public health, local government or on school boards across the country. Trump’s downplaying of the dangers of the pandemic and his hostility to mask-wearing made those stances articles of faith among his most ardent supporters – who now threaten murderous violence against those who cross them, their fury directed especially at schools that require their pupils to wear masks. In early October, the US attorney general, Merrick Garland, felt it necessary to send in the FBI to help protect school administrators, who were facing what the National School Boards Association calls “a form of domestic terrorism”. To be clear, not every Republican in the House or Senate agrees with Gosar, Taylor Greene or the Republican candidate in Pennsylvania who promised to bring “20 strong men” to a school board meeting because “this is how you get stuff done” – but they are terrified of them, just as they are terrified of Trump and his supporters. They know that if they step out of line, they will soon face an internal, primary challenge for their own seat. So they say nothing. The espousal of, or acquiescence in, political violence is the sharpest expression of Republicans’ steady march away from democracy, but it is not the only one. At the milder end is the unabashed gerrymandering under way in many of the states where Republicans are in control, redrawing boundaries to give themselves permanent and insurmountable majorities. More troubling still are the hundreds of voter suppression measures advanced by Republican state legislatures, nakedly designed to make voting harder for groups that tend to vote Democratic, especially low-income Americans and those from ethnic minorities. Whether it’s demanding stricter proof of identity, reducing early or postal voting – say, by allowing only one dropbox in each county, no matter how many people live there or how large it is – the desired goal is the same: to shrink the franchise, hurting Democrats and helping Republicans. The drive is, once again, fealty to Trump. Polls show that 68% of Republicans believe the former president’s big lie that the 2020 election was stolen from him – and they are determined to make sure it won’t happen again. To ensure there is no risk of Trump losing in 2024, Republicans are both making it harder for Democrats to vote and working to install reliable allies as election scrutineers: they want no repeat of 2020, when Republican officials allowed the votes to be counted fairly and declared Biden the winner. What is fuelling this shift is not solely the cult of personality that still envelopes Donald Trump, though that devotion is a mighty force. Studies have long shown a potent authoritarian impulse on the American right – drawn to the notion of a strong leader imposing order and guarding the nation against outsiders – one greater than in comparable countries. As always with the US, race plays a central role. Enough white Americans fear a future in which they are no longer the dominant majority and are ready to do what it takes to stay in charge: to avert demography, they’ll sacrifice democracy. This represents a mortal threat to the American republic. But the US remains the world’s most powerful nation. As of now, only one of its two governing parties is committed to democracy – and that poses a danger to us all. Jonathan Freedland is a Guardian columnist