From Value Walk:
More and more universities are trying to use a disguised heckler’s veto to prevent controversial speakers from appearing on campuses in order to avoid the added security costs often associated with such events, but a student group at the University of Washington followed his “Sue The Bastards” advice to defeat the ploy, notes public interest law professor John Banzhaf.
Many universities has simply refused to permit controversial people from speaking on campus, despite their legal obligations under the First Amendment, claiming that some students or outsiders will cause a disturbance.
This ploy is so well known that it has been given the name “heckler’s veto,” notes Banzhaf, and courts have frequently shot it down as a clear violation of free speech.
Just as those opposed to a speech cannot lawfully stop it by engaging in illegal conduct – everything from shouting it down to engaging in rioting – schools may not use the threat of wrongful conduct by one group as an excuse to prevent speech by a group with opposing views.