Because the California National Guard couldn’t be mobilized in time, Ann Coulter had to withdraw from giving a speech at Berkeley.

If you take it seriously, that’s the import of UC Berkeley’s decision to do everything it could to keep the conservative provocateur from speaking on campus over safety concerns.

“If somebody brings weapons, there’s no way to block off the site, or to screen them,” the chancellor of the university said of Coulter’s plan to go ahead and speak at an open-air forum after the school canceled a scheduled talk.

The administrator made it sound as if Coulter would have been about as safe at Berkeley as she would have been addressing a meeting of MS-13 — and he might have been right.

We have entered a new, much less metaphorical phase of the campus-speech wars. We’re beyond hissing, or disinviting. We’re no longer talking about the heckler’s veto, but the masked-thugs-who-will-burn-trash-cans-and-assault-you-and-your-entourage veto.

Coulter is a rhetorical bomb thrower, which is an entirely different thing than being a real bomb thrower. Coulter has never tried to shout down a speaker she doesn’t like. She hasn’t thrown rocks at cops. She isn’t an arsonist. She offers up provocations that she gamely defends in almost any setting with arguments that people are free to accept, or reject, or attempt to correct.

In other words, in the Berkeley context, she’s the liberal. She believes in the efficacy of reason and in the free exchanges of ideas. Her enemies do not.

Indeed, the budding fascism that progressives feared in the Trump years is upon us, although not in the form they expected. It is represented by the black-clad shock troops of the “anti-fa” movement who are violent, intolerant and easily could be mistaken for the street fighters of the extreme right in 1930s Europe. That they call themselves anti-fascist speaks to a colossal lack of self-awareness.

It is incumbent on all responsible progressives to reject this movement, and — just as important — the broader effort to suppress controversial speech. This is why former Democratic National Committee chairman Howard Dean’s comments about hate speech not being protected by the First Amendment were so alarming. In Dean’s defense, he had no idea what he was talking about, but he was effectively making himself the respectable voice of the rock throwers.

Dean’s view was that “Berkeley is within its rights to make the decision that it puts their campus in danger if they have her there.” This justification, advanced by the school itself, is profoundly wrongheaded.

It is an inherently discriminatory standard, since the Berkeley College Republicans aren’t given to smashing windows and throwing things when an extreme lefty shows up on campus, which is a near-daily occurrence.

It would deny Coulter something she has a right to do (speak her mind on the campus of a public university) in reaction to agitators doing things they don’t have a right to do (destroy property, among other acts of mayhem).

It would suppress an intellectual threat, i.e., a dissenting viewpoint, and reward a physical threat. This is perverse.

For now there is a consensus in favor of free speech in the country that is especially entrenched in the judiciary. The anti-fa and other agitators aren’t going to change that anytime soon. But they could effectively make it too burdensome for certain speakers to show up on campus, and over time more Democrats like Dean could rationalize this fact by arguing that so-called hate speech doesn’t deserve First Amendment protection.

So, it isn’t enough for schools like UC Berkeley to say that they value free speech, yet do nothing to punish disrupters and throw up their hands at the task of providing security for controversial speakers. If everyone else gets safe space at UC Berkeley, Coulter deserves one. If the anti-fa are willing to attack free speech through illegal force, the authorities should be willing to defend it by lawful force.

Heck, if necessary, call out the National Guard.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.