America's Losing Its Free Speech Consensus

Whenever issues of free speech would arise, Americans would often quote Voltaire and say, "I disagree with what you say, but I will defend to the death your right to say it." Voltaire didn't actually say it—and only a fool would count on anyone to defend them, let alone to the death. Yet it was heartening that most people felt the need to champion free-speech absolutism.

These days, another free-speech cliché is in vogue: "You don't have the right to yell 'fire' in a crowded movie theater," they retort. Those who use...