Until recently, Sohrab Ahmari was a mainstream conservative — urbane, intelligent and unfailingly good-humored — who wrote energetic defenses of classical liberalism against its enemies on both the progressive left and populist right, including Donald Trump. For several years he was also my colleague, and in some ways my protégé, at the editorial page of The Wall Street Journal.

Then Ahmari saw the light.

To be the polite conservative — the kind who presents well at, say, the Aspen Ideas Festival — was, Ahmari decided, to be a sucker. It was to play by the house rules of the culturally dominant left, in which the house always has the advantage and usually wins the game.

It was to bid for the good opinion of people who will never think of conservatism as anything other than the malignant spawn of avarice and stupidity.

From then on it would be no more Mr. Nice Conservative for Ahmari, an immigrant from Iran who is now the opinion editor of The New York Post and an ardent convert to Catholicism.

His enemies weren’t just on the left, but also on the insufficiently right.

And by insufficient, Ahmari wasn’t thinking only of ideology. He also meant those deficient in the kind of personal nastiness that is supposed to be a virtue in the right’s death struggle against progressive orthodoxies.

All this is now spelled out by Ahmari in a much-discussed (at least on the right) new essay titled “Against David Frenchism,” published in the magazine “First Things.”

For those unfamiliar with the name, David French is a longtime contributor to National Review, a legal advocate for religious liberty and free speech, an evangelical Christian, and a recipient of the Bronze Star for his service in Iraq.

In other words, an impeccable conservative — with one exception.

French is also a principled NeverTrumper, a stance for which alt-right goons trolled him on Twitter with pictures of his adopted daughter from Ethiopia photoshopped into a gas chamber, with Trump in SS uniform pushing the button.

Now it’s earned him a higher kind of mockery. “It isn’t easy to critique the persona of someone as nice as French,” Ahmari writes. “Then again, it is in part that earnest and insistently polite quality of his that I find unsuitable to the depth of the present crisis facing religious conservatives.”

Exactly what this “crisis” is, in an era where five conservatives have formed the majority on the Supreme Court for decades and abortion rights are being sharply restricted in one state after another, is a question Ahmari doesn’t really address.

But his deeper argument is that, by adhering to a classically liberal concept of a neutral public square, “Frenchism” makes too many concessions to progressives who demand that traditional conservatives bend a knee to their moral demands.

There’s something to the point that the bullying moral spirit of modern progressivism isn’t going to be mollified by David French’s niceness alone.

More likely, it will be deflated over time (and only partially) by South Park-style mockery and a natural impatience with the moral scolds of any political persuasion.

But Ahmari is after something else. What’s needed, he writes, is “to fight the culture war with the aim of defeating the enemy and enjoying the spoils in the form of a public square re-ordered to the common good and ultimately the Highest Good.”

That’s the voice of a would-be theocrat speaking, even if he hasn’t yet mustered the courage to acknowledge the conviction.

Which brings him to Trump.

Like most well-read conservatives, Ahmari was slow to warm to the president. But now the compulsively dishonest, consistently disruptive, perpetually faithless leader of the free world has morphed into something else.

“Trump understood what was missing from mainstream (more or less French-ian) conservatism,” he writes. “His instinct has been to shift the cultural and political mix, ever so slightly, away from autonomy-above-all toward order, continuity, and social cohesion.”

That’s a heroic reading of Trump’s worldview.

What he really seems to like is that the president has no interest in “civility and decency,” which Ahmari dismisses as “secondary values.”

Trump practices the kind of sucker punch, smash-mouth form of politics that, in Ahmari’s mind, is the only way of effectively fighting the encroaching cultural tyranny of the left. It’s the high church of the low blow.

I wish Ahmari were speaking for himself alone.

He isn’t. He’s just the latest conservative writer I know who has found his own way to Trumpism — proving, if nothing else, that the only things intellectuals find hard to see are the facts that stare them in the face.

Here’s what stares me in the face: Ahmari’s life story — a Muslim immigrant who wound up becoming a Trumpian moralist by way of Marxism and then free-market conservatism — is a tribute to the value-neutral liberalism he now claims to despise.

Whatever hopes remain of a decent conservative movement rest in rejecting the illiberalism he now embraces — the one that would close the door to some future Ahmari, embarking on an experiment in living all his own.

— Bret L. Stephens has been an Opinion columnist with The New York Times since April 2017.