Anglo-Saxon democracies, which were never invaded in the 20th century, have produced a rich series of alternative histories of resistance. When the Nazis win the Second World War, audiences can flatter themselves that they would never have collaborated with Robert Harris’s Fatherland or Amazon’s Man in the High Castle.

No one is more prone to imagining how well they would have behaved in conflicts that they never experienced than American conservatives. The cult of Churchill in the US would embarrass even his most devoted British admirers. From George W Bush, who placed a Jacob Epstein bust of Churchill in the Oval Office in 2001, via the CEOs who put Churchill their most admired leader, ahead of Steve Jobs, to today’s Republican leaders in Congress, the mainstream right is unanimous and unctuous in its admiration.

In truth, they are only admiring themselves. When the House of Representatives’ leader, Paul Ryan, said that for Churchill it was an “unforgivable sin” for a politician to fail to warn the electorate about an impending threat, or when John McCain compared Barack Obama to Neville Chamberlain as he cut a deal with the Castros, they were signalling their courage. Churchill and the minority of anti-Hitler Tory and Labour MPs were abused in their own parties, and beyond, until appeasement fell apart in late 1938. No matter. Like them, today’s Republicans would rather be right than be popular.

Donald Trump has proved that they are destined to be neither.

I don’t throw the word “fascism” around, but can we at least accept that Trump follows the Führerprinzip? He has no colleagues, only followers. He is a racist. Not a closet racist, or a dog-whistle racist, but a racist so unabashed that the Klan endorses him. Above all, he has the swaggering dictator’s determination to bawl opponents into silence with screams of “loser”, “dummy”, “fraud”, “puppet,” “biased”, “disgusting”, “liar” and “kook”. As with the web trolls Trump so resembles, it is never the point and always the person. Female news presenters have to explain that they are not asking him difficult questions because they have “blood coming out of whatever” or surrender to him, as Megan Kelly of Fox News did to her shame. Latinos have to explain why they are not rapists and murderers or shut up and give up. Muslims have to explain that they are not terrorists or they lose the right to a hearing. At every stage, the argument is shifted on to the troll’s terrain of ethnic and religious loyalty tests. Except here the troll could become the world’s most powerful man.

Confronted with a dictatorial menace, they lack the courage to risk the unpopularity Churchillian dissent would bring

Conservatives boasted too that they knew that the old-fashioned virtues of good character mattered as much as a man or woman’s ideology. By this reckoning, Trump’s bragging, vainglory, dark fury and towering vanity should disqualify him from the presidency regardless of his politics. Republican grandees must agree with Hillary Clinton when she said: “A man you can bait with a tweet is not a man we can trust with nuclear weapons”, not least because Marco Rubio, one of their own, has said as much himself. Yet McCain and Ryan, those enemies of appeasement, have folded and endorsed Trump. Rubio, that piercing judge of his character, has decided that, after all, Trump’s finger should be on the button. Presidents Bush père et fils are bravely abstaining. Bobby Jindal, who described Trump as a “narcissist and egomaniacal madman”, wants him in the White House. Nearly all the Republican names you remember follow suit. The Dick Cheneys, Rand Pauls and Condoleezza Rices are backing Trump or refusing to commit. Confronted with a dictatorial menace in their own time and their own country they lack the courage to risk the unpopularity that Churchillian dissent would bring.

Even when Trump followed his years of promoting the interests of a dictator of a hostile foreign power by urging Vladimir Putin to hack Clinton’s emails, they held steady in their cowardice. The Republicans, the party of red-baiters and Cold Warriors, is now in the pocket of a Kremlin “useful idiot” and the best its national security conservatives can manage are embarrassed mutters.

Only Mitt Romney, Jeb Bush and Ted Cruz openly oppose him, among prominent Republicans. And when a once mighty political movement relies on Cruz to uphold its honour it is so deep in the dustbin of history it is already composting.

My friend and comrade, the American journalist Jamie Kirchick, coined the phrase “Vichy Republicans” to describe its leaders. They don’t quite support Trump, you understand, but you surely can’t expect them to oppose him either. It is not as if America is under occupation. It is not as if the man in the high tower will order the secret police to herd them on to cattle trucks. The only suffering they will face is challenges in Republican primaries and many won’t even face that.

A little fear goes a long way. Just the possibility of being told off for challenging a candidate that they fear to be mentally unstable has been enough to persuade them to conform.

Optimists say that America’s founding fathers designed its constitution to cage men such as Trump. “An elective despotism was not the government we fought for,” said James Madison in 1788, “but one in which the powers of government should be so divided and balanced among the several bodies of magistracy as that no one could transcend their legal limits.”

But where are Madison’s checks today? Trump has already made his contempt for judicial independence clear by race-baiting and bullying a judge who was investigating one of the many accusations of fraud against him.

As for the legislature, a Trump victory would ensure a Republican-dominated Congress – those same Republicans who are too frightened to raise a word of protest against him today.

Compare them to the British Labour MPs fighting Jeremy Corbyn. They are everything that conservatives despise: hand-wringingly PC, eco-conscious, emotionally literate, bleeding-heart do-gooders every last one of them. Christ, some of them may even read the Observer. But after the killing of Jo Cox by an alleged rightwing extremist, Angela Eagle, Jess Phillips and all the other anti-Corbyn MPs who are speaking out know that the death and rape threats from left-wing extremists may not just be bluster.

They are showing true courage. Not just moral courage but physical courage. A courage that those American conservatives, who are so loud in the determination to fight the threats of the past, and so silent before the dangers of the present, entirely lack.