In Howard Brenton’s 1980 play A Short Sharp Shock, patrician Tories watch aghast as their party is suddenly populated with used car salesmen and white Rhodesian mercenaries. The play captured the nastiness of early Thatcherism so well, and so cruelly, that there were calls for it to be banned.

Today the Conservative Party is living through a second transformation, no less profound. So obsessively nationalist and xenophobic has its membership become that, with the elimination of Dominic Raab from the leadership contest, the five remaining leadership candidates alllook moderate by comparison.

A YouGov poll of party members found that more than half would rather see the destruction of their party than the cancellation of Brexit. More than 63 per cent said they would prefer Scotland to become independent, 61 per cent were prepared to see “significant damage” to the UK economy. A staggering 59 per cent wanted Brexit even if the result is a united Ireland.

The modern Tory membership sees Nigel Farage’s Brexit Party, not Labour, as its main rival — and 46 per cent would be happy if Farage became Conservative leader. That’s a long way to travel from the ethos of Harold Macmillan and Lord Carrington.

It is evidence that, whatever the outcome of the leadership race, grassroots conservatism in Britain has lost its ideological defences against the authoritarian nationalist right. It knows it does not want to be a party of open Islamophobia and misogyny, at war with the concept of truth, but it cannot remember why.

How we got here, and so rapidly, is a story of hollowing out and filling in. David Cameron’s Tories were self-confident administrators of a system that didn’t work. The free market, after 2008, turned out in fact to be wholly reliant on free money printed by the state, and on systemic insurance to banks and insurance companies from the taxpayer.

Austerity, as the left had predicted, not only destroyed the cohesion and resilience of the welfare state — it destroyed effective policing and eviscerated the armed forces. The great experiment of popular home ownership became an experiment in amateur landlordism, leaving a generation of young professionals adrift. Outsourcing was revealed as a scam, through collapse after collapse; rail privatisation likewise.

With the raison d'être hollowed out, all that was left was the shell: the party HQ, a far-right retro fashion club called the Oxford Union, the tobacco-funded think-tanks pumping out climate denial in Tufton Street, plus the depleted local associations.

The filling in phase came with large-scale entryism by the moderate wing of Ukip, as its immoderate wing swung towards outright fascism. Spurred on by Arron Banks and other Leave campaign donors, the radicalised right joined the Tories in large numbers with the express purpose of deselecting Europhile MPs and having a say in the leader who would replace Theresa May.

But the eruption of the Brexit Party has changed the game again. It is impossible to say how many actual Tory members voted for the Brexit Party in the European elections but a YouGov poll estimated at least half. So the political organism that will attempt to crown Boris Johnson king of Brexit is not really the Tory party at all. It is an elite plus an enraged plebeian mass. Which makes the outcome of the leadership race more interesting than it first appeared.

Last night’s televised BBC debate saw five privileged men in suits bellowing over each other using a weird vocabulary of sycophancy and hubris. “Thank you,” they said, to the foster mum, the Muslim and the climate protester, often followed by the assertion that “I am very proud…” and a list of their own achievements. One had started a business. Another could say the phrase “as-salaam alaikum”. All had “visions” and “detailed plans” but none could quite remember what they were. All, bar Rory Stewart, wanted simultaneously to cut taxes and boost public spending.

As I watched, it became crystal clear what was missing. First, empathy for ordinary people. Second, any overt emotional connection with the xenophobia, misogyny and anger against modernity currently being embraced by conservative-minded people. Jeremy Hunt went out of his way to attack the racist publicist Katie Hopkins. Even Johnson, when confronted with evidence of his own Islamophobic writings, said he was sorry.

As progressives, we should be expected to welcome the veneer-thin political correctness the Tory leadership candidates displayed, but it was evidence that, even now, this cosseted political caste has no idea what kind of tiger it has by the tail.

Donald Trump, and his elite backers in this country, are determined to create a political force that will disrupt our democracy, sever our historic ties with Europe, stoke race hatred and hand the NHS on a plate to US healthcare corporations. Their weapon is the Brexit Party and their chosen terrain is chaos.

Though all the Tory candidates were keen to discourage the idea of a no-deal Brexit, that is what the rightward-moving activist base of their party actively wants. Though they all tut-tutted at Islamophobia, it has already become the stock-in-trade of the street language of their supporters, just as it forms the centrepiece of right-wing tabloid discourse.

So the Tory leadership race is interesting, above all, for the disconnect it reveals between what can be said in official Conservative politics and what is being said, unofficially, in the vast and radicalised discourse of right-wing Brexitland.

When Brenton wrote his controversial satire, we at least understood what the fight within the Tory party was about: for the free market, against the remains of the welfare state; for a policy of atomisation and cruelty towards the poor; against those who wanted to maintain a paternalistic relationship to organised labour. The demographic change within the Tory membership in the late 1970s created a new kind of pushy, middle-class cynic in the Commons, who shared their purpose.

Today, however, there is no tangible shared purpose — nor can there be, with a membership that would rather see the Starry Plough flying over Stormont than forego Brexit. The crisis of Toryism has produced, among the members, literal unreason — and among the would-be leaders, paralysis. Only Esther McVey went anywhere close to conveying the nastiness of the members she wanted to represent, but she was never a serious candidate.

As it stands, Johnson looks likely to win, because only he had managed to establish a clear track record of racism, neo-colonialism and industrial-strength lying in advance of having to tone it all down for the TV cameras. But anyone expecting a “Boris bounce” thereafter is misguided.

Tory donors, even now, are trying to stitch up an electoral alliance between a Johnson-led party and Farage’s vehicle. The idea is that Farage would only stand in Leave-voting Labour marginals and against pro-Remain Tories, handing Johnson a hefty majority because of the four-way fragmentation of the vote.

But for that to happen, Johnson would have to start delivering what the new Tory faithful want, and what the Brexit Party faithful are obsessed about: he has to bash enemies, belittle his victims, lace political life with invective against feminism, Islam and political correctness. But I do not think he has it in him. Nor do I think he can assemble a cabinet that’s prepared to go along with it, unless he sidelines the entire centre of the Tory party and tries to run the government only with Eurosceptics and anti-abortionists.

So the Tory leadership debates reveal the fundamental problem of right-wing parliamentary politics. It wants to be extreme, cruel, confrontational and speak the language of the streets; but it can’t. On this basis, it doesn’t matter which of the stuffed suits wins: the Conservative Party is strategically destabilised — and will go on destabilising itself the moment one of them is handed a security pass to No. 10.

But for Labour, the cherry on the pie must surely be a Johnson premiership. Johnson’s ignorant treatment of the TV presenter Emily Maitlis, his refusal to be interviewed, his inability to answer straight factual questions, or show any empathy for the poor saps lined up to ask them, spoke to a particular symptom of privilege.

If you’ve grown up rich, and had a safe seat handed to you by the party machine, had your foolishness indulged by wives, friends and employers, and had your wages handed on a plate for writing 1,200 words of drivel every week, you become soft. Maitlis’ gentle question: “can you hear me” — as Johnson droned, stone-faced, into the camera exposed how unready for any kind of class combat he is.

A strong Labour frontbench, armed with facts and logic, staffed with young, persuasive women and people of colour will give Boris Johnson PM far more grief than his supporters currently imagine. Of all the faces lined up to succeed Theresa May, Johnson’s is the one indelibly ingrained with privilege and contempt. He is palpably part of an elite so out of touch that it does not even know how to feign concern. His very first outing in a TV debate showed that, when not allowed to lie or bluster, he is beatable.