Liz Truss is no longer strictly a political phenomenon. She is now predominantly a psychological one. Whenever she makes an intervention, you stare at her in mortified incomprehension, trying to work out which series of character flaws brought her to this place. She is a kind of political pathology.

We could easily fill textbooks with all her flaws: excessive self-belief, rank ignorance, a fetish for extreme proposals, a lack of any stabilising intellectual or cognitive functions, a total absence of any form of introspection, a seeming inability to comprehend abstract thought, and a failure to demonstrate even rudimentary presentational abilities.

But these are not the crucial aspects. The core of her psychological flaw is much simpler. She appears to be deeply and profoundly paranoid. And this makes her the perfect parable for an age in which paranoia is the chief division in political thought.

Truss’s latest genius intervention involves rushing out to praise Donald Trump just when he has brought the global economy to its knees. Her latest opinion piece for The Telegraph, a once-respectable newspaper which has now descended into populist madness, is titled: “Trump has been proven right about pretty much everything.”

You have to admire her, in a way. Most of the other writers foolish enough to be entranced by Trump at least had the bare-bone sense to betray themselves early in his second term, or just before it. Today programme presenter Justin Webb, for instance, wrote in January that “beyond the bluster, Trump may be making America normal again”. Last November, former BBC presenter Andrew Neil mocked the “largely liberal-Left American commentariat” for “seeing incipient fascism – even Nazism – in the making”.

This type of commentator now obviously looks a terrible fool. It did not require great powers of political analysis to spot the Trump danger. He had tried to overthrow American democracy. He was demonstrably mentally incapable of the job and indeed could barely speak in complete sentences. He had persistently supported far-right political views and leaders. Anyone could have seen what was happening if they had eyes to see it. Most of them, like Neil, have had the good sense to at least retract their previous complacency.

Truss, deploying her faultless political acumen, has waited until this precise moment to really stake her claim. She is impervious to the changing face of political circumstance, to the slow turning of intellectual consensus, to the deeply ingrained view of the public. She unerringly sets herself hard against any possible hint of popularity and ploughs ahead with confidence.

The criticism of Trump, Truss argues, is not a result of his failure, authoritarianism and moral squalor. It is a result of secretive powerful forces operating against him. This image of a sinister conspiracy is there throughout her piece. She speaks of an “elite… howling with indiscriminate outrage”, of a “deep state” that is “subverting democracy” and of “powerful market players” who are “not always neutral”. Her own downfall, she insists, was a result of “the economic establishment and their allies in the media”.

She reserves special vitriol for her ideological enemies, who she portrays not as opponents but globalist conspirators trying to destroy democracy and undermine their own country. Mark Carney is called “the ultimate Davos creature, sliding from failure at the Bank of England to becoming the unelected prime minister of Canada”. You would never know from this description that Truss, like Carney, became prime minister without a general election. The only difference between them is that he called an election almost immediately, whereas she did not.

Not so long ago, you would never have read this kind of deranged screed in a mainstream British newspaper. Conspiracy theories were considered the work of stoners and fruitcakes. But this kind of thought has now colonised the mainstream right.

The irony is that Truss is actually Trump’s ideological opposite. Her own downfall came because she pursued a mini-Budget dedicated to free market neoliberalism. She wanted to reduce taxes, eliminate state intervention in the economy and scrap regulations. Trump’s efforts are in precisely the opposite direction – he is raising tariff barriers between countries. His actions of the last weeks damage and destroy free market economic structures.

But these sorts of ideological comparisons belong to the old world. Back then, we would debate things like resource allocation, free trade and state regulation as the core distinction in political thought. And we would disagree furiously, but we were all discussing the same shared reality and accepting the same shared data to verify it.

This is no longer a meaningful distinction in modern political thought. The great divide today has nothing to do with tariffs or taxes. It is between the paranoid style and reason itself. On the one hand we have those who believe in some monstrous conspiracy of elites – in universities, the media, finance, the civil service, parliament and the judiciary – which is undermining the nation. And on the other we have those – on left and right – who still believe in reason, rationality, empiricism and evidence. Who still believe in Enlightenment values.

Truss’s economics could not be further from Trump’s. But they are aligned on the only thing that matters nowadays: the paranoid takeover of the conservative right. They’re just as mad as each other, and that’s why she loves him.