by Jacob Sullum

About the author: Jacob Sullum is a syndicated columnist and a senior editor for Reason,a monthly libertarian magazine.

In the Norman Rockwell painting “Freedom of Speech,” an earnest Everyman stands at a public meeting to offer a question or comment. Judging from his mild expression and the polite attention of the people around him, he is not saying anything offensive or threatening.

Maybe he is asking for a new stop sign, complaining about an unfilled pothole or suggesting a raffle to raise money for the next Founders’ Day celebration. Whatever it is, chances are he’d be able to say it without a constitutional guarantee.

The painting nicely captures how most Americans view the First Amendment, which they love in theory but often abhor in practice. They are...