In the vice presidential debate Tuesday, Minnesota Gov. Tim Walz pulled the fire alarm.

His opponent, Sen. JD Vance, R-Ohio, cited the massive system of censorship supported by Vice President Kamala Harris and her running mate.

Walz proceeded to quote the line from a 1919 case in which Supreme Court Justice Oliver Wendell Holmes said you do not have the right to falsely yell fire in a crowded theater.

It is the favorite mantra of the anti-free speech movement. It also is fundamentally wrong.

In my book "The Indispensable Right: Free Speech in an Age of Rage,” I discuss the justice's line from his opinion in Schenck v. United States. Holmes wrote, “The most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic.”

As I discuss in the book, the line was largely lifted from a brief in an earlier free speech case. It has since become the rationale for politicians and pundits seeking to curtail free speech in America.

For example, when I testified last year before Congress against a censorship system that has been described by one federal court as "similar to an Orwellian ‘Ministry of Truth,’” Rep. Dan Goldman, D-N.Y., interjected with the fire-in-a-theater question to say such censorship is........

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