When you have a student-on-student shouting match, the First Amendment may be stretched to the breaking point. When professors join in the fun, as happened recently at the University of Nebraska at Lincoln, it may well tip the balance, for better or for worse. "On August 25, University of Nebraska–Lincoln sophomore Kaitlyn Mullen set up a literature table outside the student union to promote Turning Point USA, a libertarian/conservative campus-based organization," David Moshman writes on the academe blog maintained by the American Association of University Professors (AAUP). "PUSA proclaims its support for free speech but maintains Professor Watchlist, a blacklist...