Avisit to Conservative party conference is like being transported to the recent past of another country. When the US Republicans were routed in 2008, the seeds of what they would become – a party defined by conspiratorial far-right populism – were being planted. The newly elected Barack Obama intended to establish a communist dictatorship with a Gestapo-like security force, claimed one Republican congressman. Fox News became a key engine of a new conspiracism, not least the notorious “birther” lie, falsely alleging the president was not a native-born American. The Republican establishment leaned into this fanaticism: take the salutary example of Liz Cheney, daughter of George W Bush’s vice-president, who defended the birther lie at the time. She helped feed a conspiratorial far right that found itself a demagogic figurehead in Donald Trump, whom she would later go on to denounce. There was no shortage of Tory Liz Cheneys at conference. Take the transport secretary, Mark Harper, who took to the stage to endorse a conspiracy theory that, until now, has been the preserve of far-right internet trolls. The idea behind 15-minute cities could hardly be more innocuous: we should all be a 15-minute walk or bike ride away from everyday services we depend on, like GP surgeries, shops and banks. But Harper told the assembled faithful that local councils will dictate “how often you go to the shops”, “ration who uses the roads”, and then enforce it with CCTV surveillance. This is a lie, and Harper knows it. When his ministerial colleague, Andrew Bowie, subsequently defended this conspiratorial nonsense, arguing that voters were concerned that their “liberties were going to be infringed”, he must have known it was a hoax too. Perhaps they believe that indulging far-right conspiracism will attract its delusional believers to the Tory fold, and prevent them defecting to Nigel Farage’s Reform UK party. A more likely outcome is this worldview will be legitimised and pave the way for more extreme politicians. This week in Manchester, Farage strode around the conference like a hungry crocodile, sizing up his prey. The rock-star reception he attracted suggests the faithful would quite like to be eaten. Farage has partly remoulded the Conservatives in his image by menacing them from the outside. It may well be that he will stick to his devastatingly successful strategy, using external leverage to keep coercing the Tories into adopting his agenda. If Farage successfully stands for parliament on his eighth attempt, this time wearing a blue rosette, the party will one day surely be his. He floated rejoining the party if the demagogic home secretary, Suella Braverman, takes the Tory crown: “at least I’d believe in some of the policies”, he said, when I spoke to him at conference. It would be easy to dismiss this conference as revealing a party suffering a breakdown in advance of a shattering defeat. Tory delegates struggled to tell me what the Conservatives’ lasting achievements after 13 years in office even are. If so many at this flat, sparsely attended conference have given up, why should the rest of us fear a party enduring an identity crisis? Look again across the Atlantic. The Republicans, it was believed, became so unmoored from reality that permanent electoral Armageddon beckoned. Hillary Clinton’s team craved Donald Trump as their opponent for that very reason. And now? Just ask Cheney how that worked out. So consider this for a scenario. Labour triumphs at the next election, but wins by default and with no enthusiasm for Starmerism in the tank from the start. Unlike 1997, the new administration rules a country defined by turmoil and decline, but offers no transformative policies to answer our multiple and overlapping crises. Disillusionment sets in, while the Tories complete their metamorphosis into loud, proud, brash rightwing populism, hoovering up votes from the disaffected. In the general election of 2029, a new model Tory party – flushed with British Trumpism – stages a stunning comeback. True, this is not the US: your gut instinct may say it can’t happen here. But when, in the past, you looked in bemused horror at their culture wars, you may have assumed they’d never arrive on our shores – but they did. Farage marched through conference not as a hostile outsider, but as a conquering general. His mission is not yet complete, however, and a final prize may beckon. Owen Jones is a Guardian columnist