Brexit supporters expect “the elite”, “the establishment”, “the Westminster bubble” to “rig the system” to stop them “taking our country back”. The enemy imposed metric measurements, drink-driving laws, immigrants and smoking bans and now it wants to stop Brexit. They take us for fools. They think we are stupid.

And yet their actions show that cynics who doubt everything trust Nigel Farage, even though he takes them for absolute idiots. It was an education to watch him make his offer of a Leave alliance to Boris Johnson on Friday. Farage’s warm-up acts played all the old tunes. Richard Tice, a property investor who has the well-cut suits and fading good looks of the type of charmer who cons widows out of their savings, said the Tories lived in the “stinking rotten borough of Westminster”. Claire Fox, who, satisfyingly, looks as malicious in the flesh as you would expect a member of the Revolutionary Communist party who ended up on the hard right via a spell denying the massacre of Bosnia’s Muslims to look, followed up. The Tories were among the elitists, scoffing behind their manicured hands and calling Brexiters “xenophobes, ignorant and far right”. Ann Widdecombe came next. I won’t pretend to understand all, or most, of what she said. But her drift was that the Tories were a pack of liars who would betray Brexit and all who believed in it.

Compromise would betray the Brexit purists. But Farage and Johnson are already betraying them

Farage then strode to the stage like a televangelist to the pulpit. He posed as the last honest politician in England. Unless Johnson agreed to ditch his deal with the EU, he would run Brexit party candidates against the Conservatives in every seat. Liberals were ecstatic. As Johnson cannot agree to destroy his own settlement, Remainers were relieved. The pro-Remain campaign group Best for Britain estimates that an unspoken agreement between the Brexit and Conservative parties could deliver Johnson a comfortable majority. Now Agent Farage, the Remainer mole, was sabotaging the Tories’ chances and with them the chances of Brexit.

Yet for a supposedly iron man, Farage sounded remarkably flexible. He praised Johnson’s energy and sympathised with his difficulties. He emphasised that he had until mid-November to decide where to run candidates and would almost certainly not run them against the Tory right. “This is a ferret searching for a hole to reverse down,” I thought.

The election campaign has achieved what many thought impossible and lowered the standards of public debate. Johnson does not have a “deal” with the EU, merely a withdrawal agreement. Every circle of hell remains available for Britain if his Brexit passes, including a few the devil himself has yet to discover.

Farage could spin a quiet rapprochement with Johnson a dozen different ways. We remain in the single market and customs union until December 2020. Johnson hopes to negotiate a trade agreement by then. But trade deals take years to complete. Farage and the Tory right could tell their followers we could crash out in December or in June, when we would have to ask for an extension to the transition period to keep the negotiations going.

Farage could say he would stand down candidates to stop Corbyn. He could say that he had discovered a “Canada-style trade deal” is possible and rely on the fact that the majority of people do not know what a Canada deal is or why the EU would demand harsher terms from Britain than it demands of a country thousands of miles away.

if there is any meaning in the word, 'populism' can be defined as the willingness of voters to be lied to

Compromise would betray Brexit purists. But Farage and Johnson are already betraying them. Both say they expect to win in south Wales, the north of England and Midlands, the very areas whose manufacturing industries would be hardest hit by pulling us out of the single market.

Then there is the revealing game Farage has played with Brexit party members, which shows how little he thinks of them. He persuaded at least 3,000 to apply to become parliamentary candidates and charged them £100 apiece for the privilege. Yet when the candidates were announced, there were many of the same faces from Farage’s Ukip days or Fox’s Revolutionary Communist turned Reactionary Chauvinist party. Otto English of the Byline Times, who covered the story, received private emails from working-class hopefuls who said they were told to campaign in byelections to “increase your chances of being selected”. When they got there, no one took their names. Straight afterwards, they received a “you have not been selected” mass email.

Individuals have walked away from Farage. But his core stayed loyal, as the core of populist movements always does. For if there is any meaning in the vapid word, “populism” can be defined as the willingness of voters to be lied to. The louder they scream “all politicians are liars”, the harder they fall for the big lie from their chosen demagogue. Political scientists define devoted supporters of Farage, Trump and Corbyn as “low-trust” voters, who believe nothing they hear on the news. And yet they turn as trusting as children when their great leaders lead them on. In the case of Brexit, they are easy to lead and to fool. The divide in Brexit Britain is not based on class but on age and education: 70% of voters whose educational attainment was only GCSE or lower and 64% of over-65s voted to leave.

I am not saying that having a degree ensures you are wise or even clever or that every pensioner is suffering from mental decline. But there are good reasons why pyramid sellers and faith healers prey on the uneducated and conmen target widows. If you want people to fleece, these are your best prospects.

“Some ideas are so stupid that only intellectuals can believe them,” runs the old line. But the converse also applies. Some ideas are so stupid that only the uneducated can believe them – and Farage is proving that Brexit is top of the list.

* Nick Cohen is an Observer columnist