Kevin Williamson has been fired from The Atlantic. Since leaving National Review in March, the conservative writer has managed to produce just one column at his new perch, in which he declared the death of the libertarian moment.

But the thing that cost him the gig was a remark he made on a podcast well before his firing and in a tweet (since deleted [UPDATE: Williamson notes that his account is deactivated, not that this specific tweet was deleted]):

And someone challenged me on my views on abortion, saying, "If you really thought it was a crime, you would support things like life in prison, no parole, for treating it as a homicide." And I do support that. In fact, as I wrote, what I had in mind was hanging.

Williamson expressed the view that abortion is murder and should be punished to the full extent of the law (although he also later indicated that he has mixed feelings about capital punishment). I do not share his view. But by declaring Williamson to be outside the Overton window of acceptable political discourse because he believes strongly that abortion is a serious, punishable crime, The Atlantic is essentially declaring that it cannot stomach real, mainstream conservatism as it actually exists in 21st century America.

Williamson uses colorful and sometimes rash language. He didn't have to detail the grisly form of punishment he would inflict on women who decide to terminate their pregnancies. He chose to do so because he enjoys provoking a reaction. But The Atlantic knew that about him before it hired him.

Editor Jeffrey Goldberg says he decided to fire Williamson only after learning that the tweet and podcast quote "represented his carefully considered views." But the underlying logic of Williamson's pro-life position is a view shared by roughly half or at least 40 percent of Americans.

It is, of course, the perfect right of The Atlantic's editors to publish whomever they wish. Reason staffers are all libertarian, under a big-tent understanding of that term (not to brag, but we are repping the pro-life view). That's written into our mission as a magazine. But if The Atlantic purports to capture a broad spectrum of American political views, Williamson's firing is a sign that it hasn't yet figured out how to do so. And the reader outcry against him (and his rightish heterodox kinfolk at The New York Times) is a sign of a market that has grown increasingly squeamish about a genuinely inclusive journalistic vision.

I have personally been the beneficiary of this doublethink on ideological diversity for years. When institutions recognize the need to have a nonliberal somewhere in their midst, they look across the landscape and discover that the closest thing to conservatism that they can tolerate is a relatively mild-mannered, young(ish), female, pro-choice libertarian. Which is to say, not a conservative at all.

The Atlantic publishes lots of interesting heterodox voices, of course. And I'd like to think I do provide ideological diversity in situations where I've been called in. But putting me on a panel is not nearly the same thing as giving the conservative side of the American political spectrum a hearing.