There was a time when people looking for intellectual debate turned away from politics to the university. Political backrooms bred slogans and bagmen; universities fostered educated discussion. But when students in the 1960s began occupying university property like the thugs of regimes America was fighting abroad, the venues gradually reversed. Open debate is now protected only in the polity: In universities, muggers prevail.

Assaults on intellectual and political freedom have been making headlines. Pressure from faculty egged...