So now, the question gaining traction is: why "death panels"? Why this particular smear?
Keeping in mind that I think that most of what's happening out in the town hall meetings is a sideshow, it still is an interesting question, I think. Andrew Sabl speculates that it has to do with the particular context of the bills being developed; Mickey Kaus and Eugene Robinson (via the Dish) think that it's the result of Obama's mistaken emphasis on cost containment, instead of new benefits.
I'm with Robert Wright on this one. The opposition was going to make far-fetched claims, and which particular ones get made and then become part of the shouting matches on cable news, talk radio, and the town halls doesn't really have anything at all to do with what the proponents of the bill are saying, or what they put into the legislation.
The evolution of this particular claim is clear: it was propagated by the recent Republican Vice Presidential candidate, a woman who is also one of the handful of leading candidates for the Republican nomination for president in 2012. The news media is wired to treat things that such people say as news. Palin's crazy talk drowns out (at least to some extent) the crazy talk from the Becks and the Hannitys; that's how the system works. Normally, leading presidential candidates restrain themselves from talking out of their hats, but Palin either doesn't know better or believes its in her self-interest to act as if she doesn't know better. But rest assured: had she talked about communism or Hitler or, let's make up one, how Obamacare would require all doctors to recognize gay marriage, then that would have been the headline. My strong guess is that Palin (or Michelle Bachmann, who she apparently got it from) didn't poll or focus group this one; Palin and Bachmann just say crazy things because, well, because they say crazy things.
The story isn't why a particular smear was spread; the story is that Democrats treat their nutty Members of Congress as pariahs (yes, that's you, Cynthia McKinney) while (some, but some high-ranking) Republicans treat theirs as intellectual leaders. Meanwhile, the rest of us can enjoy the convoluted explanations Republican talking heads come up with to explain why it's perfectly appropriate for someone to say that something that's not in a bill is, in fact, in the bill (I saw someone -- Tony Blankley, maybe? -- arguing on TV this evening that since Obama once wondered out loud about whether heroic end-of-life efforts are always worthwhile, the only logical conclusion was that once a non-death-panel bill passed he would most assuredly stop treating anyone with something more serious than a cold. Or something like that).
Oh, and while I'm at it, I still think that Joe Biden should challenge Sarah Palin to a televised debate.