It would be charitable to ignore Liz Truss. Attention is her addiction and any dose, even laced with scorn, sustains the toxic belief that she has important things to say. Britain’s shortest-serving prime minister has been bingeing on publicity for a memoir that cannot enhance her reputation. She is a stranger to contrition. She regrets only the haste with which she tried to implement an economic plan that she believes was sabotaged by the establishment. She thinks the meltdown in financial markets that brought her down was engineered by the Bank of England and the Office for Budget Responsibility. Truss’s bizarre demeanour, self-regarding without self-awareness, limits the purchase her ideas might get on public opinion, even with audiences primed for conspiracy theory. The loudest cheers when she appears on television are from the Labour party. Rishi Sunak would rather forget she even exists, which is one reason to keep the flame of memory burning. To dismiss Truss as an irrelevance is to collude with Conservatives who want to pretend that she never happened. But she did. She was imposed by Britain’s ruling party, chosen by its members in preference to the current prime minister. When Sunak was later installed as Truss’s replacement he was flattered by the contrast. He passed basic tests of coherence and financial sobriety that she had failed. The previous summer, he had warned against the “fairytale economics” of promising billions of pounds in tax cuts without any credible costing or revenue projections. On that point, the new prime minister was vindicated. He embodied the repudiation of his predecessor, which spared him having to explain other differences between them. It was the same with regard to Boris Johnson. When Sunak resigned as chancellor in July 2022, his given motive was public expectation that Britain be governed “properly, competently and seriously”. Nearly two years later, he still hasn’t named any of the improper, incompetent or unserious things Johnson did, or explained why he never said anything at the time. Sunak has defined himself against failure and disgrace, taking care never to be precise about the nature of the offences. He hoped ambiguity would buy him loyalty. Instead, it has meant surrendering control over the debate about the future of Conservatism and relinquishing any claim to moral authority outside the party. The prime minister’s most ambitious exposition of a guiding doctrine was the speech at last year’s Tory conference, where he complained that Britain has been held back by “30 years of vested interests” and a “failing political status quo”. He cast himself as the change the country needed. As an abdication of governing responsibility coupled with delusional self-regard, it was Trussite. Sunak has not returned to the theme. These days the closest thing Downing Street has to a vision of the future is Britain as a country where smoking gets a bit more illegal every year. That creates a void for Truss to tout her surplus zeal. The ludicrous messenger discredits the message. But Truss’s argument still stands out as the most prominent expression of what Tories should believe about the recent past and the near future; why western civilisation is imperilled and how it can be saved. It might rest on grotesque distortions of history and resistance to facts, but advocates of reality in the Conservative party are not putting up much competition. The core proposition is a facile cult of political freedom, defined as minimal taxation and horror of state interventions that prioritise collective social obligation over individual enterprise. A fundamentalist concept of liberty is then used to flush out a disparate coalition of enemies – the Chinese Communist party, Joe Biden’s industrial strategy, woke academia, unsupportive journalists, the UK supreme court and, of course, the European Union. This is the ethos that led Truss to declare herself unsure whether Emmanuel Macron was “friend or foe” in a leadership hustings. It leads her to endorse Donald Trump (although it can be hard to separate conviction from cupidity when British politicians get a taste of the lucrative US rent-a-fanatic circuit). There is no way to configure Trump and the Kremlin fandom rife in the Republican party as defenders of “the west” without stripping that word of all previous historical and geopolitical connotation. But there isn’t much point looking for intellectual consistency in a movement that measures conservative virtue in contempt for established institutions and constitutional norms – the opposite of conserving things. Truss is hardly the only purveyor of that spirit in British politics. Her dry libertarian blend competes with the spicier nationalist flavour associated with Nigel Farage. (There is also an evangelical Christian variant on the Tory backbenches.) There isn’t much evidence that politics tuned to the hysterical pitch of American conservatives resonates across the Atlantic. Tory voters like socialised healthcare more than guns. A recent poll ranking foreign politicians by popularity in Britain put Trump behind Joe Biden, Hillary Clinton, Bill Clinton, Emmanuel Macron and Angela Merkel. (Barack Obama came top.) Those public preferences don’t inoculate the Tory party against ideological contagion, especially once ousted from power. In the competition to explain election defeat, the account that blames the establishment, high taxes, flaccid leadership and an electorate brainwashed in leftism has a head start. It is the story already being told to explain present unpopularity and the absent Brexit dividend. And while it is better to have a conspiracy cult in opposition than in government, the health of British democracy will suffer if the Tories completely relinquish their grip on reality. If the Conservative party flees the arena of rational debate, an influential and well-financed media circus will follow; the frame around political debate will warp. There aren’t enough Trussite MPs, let alone Truss-supporters in the country, for the former prime minister to inspire much beyond ridicule. But if hers is the only story anyone can hear, what does that say about the other Conservatives? Sunak was sold as a remedy, and the patient hasn’t revived. What do the moderates, the One Nation liberals, the queasy centrists – the serial backers of losing candidates – do next? They don’t have a leader; they don’t have an argument. Next they could end up without a party. Rafael Behr is a Guardian columnist