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.

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 against health reform to the campaign against Social Security privatization back in 2005. But there’s no comparison. I’ve gone through many news reports from 2005, and while anti-privatization activists were sometimes raucous and rude, I can’t find any examples of congressmen shouted down, congressmen hanged in effigy, congressmen surrounded and followed by taunting crowds.

And I can’t find any counterpart to the death threats at least one congressman has received.

So this is something new and ugly. What’s behind it?