The United States’ supposed lurch toward authoritarianism — or maybe full-on fascism — has become an obsession among progressives and even a few centrists and conservatives. George Orwell’s “1984” and Sinclair Lewis’s “It Can’t Happen Here” are once again bestsellers; well-known liberal intellectuals, discoursing on the term’s definition, have categorically called President Trump a fascist; and left-leaning websites murmur warnings of another Reichstag fire.

Leave aside the facile parallels (Mussolini was a bully, and so is Trump!) and consider the larger point that, if fascism was going to spread to the United States, it would have done so in the 1920s and 1930s, when fascism and related ideologies were gaining the support of enlightened, forward-thinking people all over Europe. Authoritarian and antidemocratic movements were taking hold nearly everywhere from Portugal and Spain in the west to Greece and Russia in the east. For European intellectuals and politicos, democracy wasn’t the future; fascism and communism were. Yet neither ideology attracted more than a few adherents in the United States. The salient fact about Lewis’s “It Can’t Happen Here” — to repeat the common quip — is that it didn’t.

[Why the left is suddenly so fascinated with authoritarianism]

The general term for the mystery is “American exceptionalism”; socialists have spent decades lamenting this exceptionalism or explaining it away, and conservatives have rejoiced in it. But there is no argument over the fact that the radical ideologies of the 20th century failed in the United States.

You could argue that fascism is reemerging in some new and more domestically engineered form. Yet that would be to misunderstand not just the history of fascism but also the character of American society itself. There is a reason neither fascism nor communism nor socialism ever took root in the United States, and the reason remains: These ideologies are premised on the centralization of authority, and the dominant tendency of American culture is always centrifugal. It’s a consequence of our federalist system, which itself is a consequence of the frontiersman’s attitude of American settlers and immigrants — self-governing in lifestyle, Protestant or unorthodox in religion, contemptuous of distant authority.

Fascism, in order to thrive, needed conformity and deference to the wisdom of planners. It was the doctrine of elites, not mavericks or crackpots. The Nazis purged many accomplished people from high positions, but most of the elites either tolerated or supported them. They captured the government first, but the universities, the established churches and the cultural institutions soon fell into line. That didn’t work in the United States for the simple reason that Americans — despite some centralizing strains in progressivism — have never thought of their nation as an amalgamated, monolithic thing, governed by a rational aristocracy from the center. As for Trump’s chances of effecting a fascist putsch, does anyone seriously imagine that his populist creed stands a chance of winning over the elites who populate our universities, news media, cultural institutions and entertainment industry?

This entire discussion, though, assumes that the tenets of Trump’s ideology, the content of his decisions and policies insofar as we know what they are, bear some relationship to fascism. They don’t. Only the president’s stringent immigration policies, expressed foolishly in his executive order on travel visas, gives an appearance of credibility to parallels with European fascism; but the parallels work only if you believe Trump’s views on immigration arise from a desire for racial purity rather than a misguided obsession with national security. I do not hold that belief, primarily because Trump is far too much of a globe-trotting libertine to give a fig about any racial theory. Some of his supporters are bigots, no doubt, even as some of Bernie Sanders’s supporters are communists; I assume the latter would have been disappointed, and the former will be soon enough.

[Why Trump’s rant over leaks won’t help him]

Otherwise the constituent parts of Trump’s political worldview, though strange to be sure, look nothing like fascism or radicalism of any kind. That so many liberal journalists and intellectuals have interpreted Trump’s ascendancy as the nascence of despotism — think of the hysterical response to Stephen K. Bannon’s remark that the media should “keep its mouth shut and just listen for a while” — says far more about their delicate sensibilities than it does about the Trump administration.

But if this populist upheaval isn’t fascism or anything close to it, what is it?

The Trump phenomenon is a distinctly American upheaval: ugly in its overtones, philistine in its aesthetics, incoherent in its tenets, occasionally disruptive of valuable traditions and institutions, but basically a necessary remedy to the centralizing dynamic of consensus liberalism. “It is certainly true,” wrote the neoconservative intellectual Irving Kristol in 1995, “that any kind of populism can be a danger to our democratic orders. But it is also true that populism can be a corrective to the defects of democratic orders — defects often arising from the intellectual influence, and the skillful entrepreneurial politics, of our democratic elites.”

Today’s democratic elites — the liberals and progressives who run our institutions — have become too complacent in their dominance and too conformist in their opinions. The populist movement that’s turning our politics upside down won’t win them over, but it will weaken their influence and rattle their pieties. And when the dust settles and the United States is still the free and vibrant place it was before — when the nation hasn’t metamorphosed into some fascist dystopia — they just might engage in a little self-criticism.