There’s a famous Norman Rockwell painting titled “Freedom of Speech,” depicting an idealized American town meeting. The painting, part of a series illustrating F.D.R.’s “Four Freedoms,” shows an ordinary citizen expressing an unpopular opinion. His neighbors obviously don’t like what he’s saying, but they’re letting him speak his mind.

Paul Krugman

That’s a far cry from what has been happening at recent town halls, where angry protesters — some of them, with no apparent sense of irony, shouting “This is America!” — have been drowning out, and in some cases threatening, members of Congress trying to talk about health reform.

Some commentators have tried to play down the mob aspect of these scenes, likening the campaign...