“How the hell do I know what I find incredible?” a bemused philosopher asks in Tom Stoppard’s play “Jumpers.” “Credibility is an expanding field … and sheer disbelief hardly registers on the face before the head is nodding with all the wisdom of instant hindsight.” This is a now familiar emotion, a recognizable expansion. The unimaginable happens—Donald Trump, fool, oaf, and sociopathic liar, becomes the nominee of a major American political party—and within minutes what ought to be a shock beyond understanding becomes an event to savor, accept, and analyze. The desperate efforts to normalize the aberrant begin: he’s actually a Rockefeller Republican with orange hair; he wasn’t humiliated by President Obama’s mockery at that dinner in 2011 but responded as a lovable, gregarious good guy; even his birtherism wasn’t the vile racist sewage anyone could see it to be—he was genuinely unsure about where exactly it was the President was born. Trump tells one wild ranting lie after another on Sunday-morning television—we are the most heavily taxed nation in the world; he always opposed the Iraq war—and Chuck Todd can’t do much more than nod and say “Gotcha!”

This is the kind of desperate response to the rise of fascism one might expect to find in a decadent media culture. Neocons have made a fetish of 1938; in retrospect they would have done better looking hard at 1933. There is a simple formula for descriptions of Donald Trump: add together a qualification, a hyphen, and the word “fascist.” The sum may be crypto-fascist, neo-fascist, latent fascist, proto-fascist, or American-variety fascist—one of that kind, all the same. Future political scientists will analyze (let us hope in amused retrospect, rather than in exile in New Zealand or Alberta) the precise elements of Poujadisme, Peronism and Huck Finn’s Pap that compound in Trump’s “ideology.” But his personality and his program belong exclusively to the same dark strain of modern politics: an incoherent program of national revenge led by a strongman; a contempt for parliamentary government and procedures; an insistence that the existing, democratically elected government, whether Léon Blum’s or Barack Obama’s, is in league with evil outsiders and has been secretly trying to undermine the nation; a hysterical militarism designed to no particular end than the sheer spectacle of strength; an equally hysterical sense of beleaguerment and victimization; and a supposed suspicion of big capitalism entirely reconciled to the worship of wealth and “success.” It is always alike, and always leads inexorably to the same place: failure, met not by self-correction but by an inflation of the original program of grievances, and so then on to catastrophe. The idea that it can be bounded in by honest conservatives in a Cabinet or restrained by normal constitutional limits is, to put it mildly, unsupported by history.

To associate such ideas too mechanically with the rise of some specific economic anxiety is to give the movement and its leader a dignity and sympathy that they do not deserve. In France, Jean Marie Le Pen’s voters are often ex-Communists, working people who also believe their national identity to have been disrupted by immigration. That does not alter, or make more sympathetic, the toxic nature of his program; the ideology that it resonates to is an ancient and persistent one, that thrives through good times and bad. That Trump can dominate an increasingly right-wing nationalist party with a right-wing, white-nationalist creed is neither surprising nor all that complicated. Anyway, the notion that a class cure can be had for a nationalist disease was the persistent, tragic delusion of progressive politics throughout the twentieth century.

The question is about action and here, as has been said before in this space, the best parallel in modern politics occurred in the French Presidential election of 2002, when the left and right joined to form a Republican Front—ironic term—designed to keep Le Pen from power. The lines of a similar Republican front seem dismayingly harder to see here. Almost every intelligent conservative knows perfectly well who Donald Trump is and what he stands for. But NeverTrump is a meaningless slogan unless one is prepared to say ThisOnceHillary.

Some may be waiting for a third choice to emerge, an honorable if improbable idea, but too many seem hobbled by a disdain rooted less in rationality than in pure habit to see the reality of the circumstance. This kind of Republican front would not really require that anyone formally endorse Hillary’s politics, which they have every right to resist and criticize. But voting against Trump is an act of allegiance to America. Even if Republicans are persuaded that she is Claire Underwood out of “House of Cards”—well, Claire Underwood is a more stable person to have in office than a cross between Sauron and Bozo the Clown. What would Hillary Clinton be like in the White House? Well, she was in the White House, once, and helped preside over a period of peace and mostly widespread prosperity. One can oppose her ideology (to the degree she has any), be unimpressed by her record (as contradictory as it may be), or mistrustful of her character. God knows, it is bitterly hard to defer to a long-standing political enemy, but it is insane to equate a moderate, tested professional politician with a crypto-fascist. Doing so is possible only through a habit of hatred so distended that it no longer has any reference to reality at all.

Hitler’s enablers in 1933—yes, we should go there, instantly and often, not to blacken our political opponents but as a reminder that evil happens insidiously, and most often with people on the same side telling each other, Well, he’s not so bad, not as bad as they are. We can control him. (Or, on the opposite side, I’d rather have a radical who will make the establishment miserable than a moderate who will make people think it can all be worked out.) Trump is not Hitler. (Though replace “Muslim” with “Jew” in many of Trump’s diktats and you will feel a little less complacent.) But the worst sometimes happens. If people of good will fail to act, and soon, it can happen here.