During a dinner for students that the dean of the University of California, Berkeley law school held in his house’s backyard earlier this month, a woman wearing a hijab and checkered Palestinian scarf suddenly stood up with a microphone and amplifier. What followed lasted only a couple of minutes, but has led to a fierce debate about the limits of free speech, drew death threats to those involved, and created a “media firestorm,” as the dean, Erwin Chemerinsky, has put it. Some short and chaotic viral videos illustrate part of what happened. One of them shows the woman, Malak Afaneh,...