“Brown cultivates a spirit of free inquiry,” writes its President, Christina Paxson, on her website. “Brown prizes the intellectual exchange that is sparked by a diversity of views and experiences.”

Tell that to Ray Kelly. Yesterday the New York City police chief was prevented from speaking on Paxson’s campus by students angered by the NYPD’s racial profiling. Those students have good reason to be angry. Unfortunately, they’re the latest in a long line of campus activists who believe their anger trumps other people’s free speech.

Kelly is only the most recent victim. In 2002, protesters prevented Benjamin Netanyahu from speaking at Montreal’s Concordia University. In 2009, activists at the University of North Carolina shut down a planned speech by anti-immigration congressman Tom Tancredo.

There’s something deeper going on here. On the surface, campuses like Brown’s seem hegemonically liberal. But in my experience, that apparent consensus conceals a crucial gulf between students and faculty who hold left of center opinions but accept basic norms of fair play and students who consider freedom of speech a scam employed by the powers that be to perpetuate their racism/sexism/classism/imperialism/homophobia. Convinced that freedom of speech is an illusion denied them outside the university gates, they take revenge in the one arena where the balance of forces tilt their way. And they thus inject into their own campuses the totalitarian spirit they believe characterizes society at large. It’s no surprise that such activists targeted Ray Kelly, and that for years they tried to bar military recruiters. What better way to deny your government’s basic legitimacy than to turn the people it deputizes to protect you into pariahs.

In 1949, when some American liberals still believed they had more in common with Joseph Stalin than Robert Taft, Arthur Schlesinger famously argued that people on the left and right who believed in democracy and individual rights must form a “vital center” against totalitarianism in both its right-wing (Nazism) and left-wing (Stalinism) guises. (In practice, “vital center” liberals didn’t always live up to their own rhetoric about civil liberties, but that’s another column).

Growing up at a time when both fascism and communism had lost their appeal, I didn’t fully grasp Schlesinger’s argument. Until one day in college when I read a head-snapping review in The New Republic by the late Marxist historian Eugene Genevose. Genevose was reviewing Dinesh D’Souza’s book Illiberal Education, which alleged that campus leftists were threatening free speech. I hadn’t read the book, but as a good liberal, I loathed D’Souza, the Andrew Breitbart of his time, and expected Genovese to savage it.

He didn’t. To the contrary, he lauded D’Souza’s “chilling” account of the “atrocities” against free expression that “ravage our campuses.” And he argued that “as one who saw his professors fired during the McCarthy era, and who had to fight, as a pro-Communist Marxist, for his own right to teach, I fear that our conservative colleagues are today facing a new McCarthyism in some ways more effective and vicious than the old.” The more I learned about the examples D’Souza detailed in his book—some of which echoed things I had seen at my own university—the more I realized that Genevose was right. When it came to free speech, America still needed a “vital center.” It included both Dinesh D’Souza and Eugene Genovese and it might as well include me.

To my mind, Ray Kelly’s policies towards African Americans, Latinos and Muslims are abusive and unfair. I cringed at the prospect of him becoming Secretary of Homeland Security. But that’s beside the point right now. Every decent liberal should defend his right to speak against the latter-day totalitarians who denied it yesterday. If I remember correctly, Genovese concluded his review with an appeal to people across the ideological spectrum who believe universities must remain open to incendiary and unpopular ideas. “It’s time,” he wrote, “to close ranks.”

It still is.