It's all about spooking Members of Congress.
That's why those opposing health care reform are packing town hall meetings, and that's why liberals who support reform are at such pains to discover "Astroturfing," and so sensitive to suggestions that protesters are part of a genuine popular ambivalence on reform.
Again, back to what's going on. Members of Congress are highly risk-averse. They attempt to avoid risk by avoiding controversial votes. So this isn't exactly about whether majorities favor reform or not; it's about whether the vote is going to be perceived by politicians as endangering their careers.
Democrats in Congress won't be spooked, or at least are a lot less likely to be spooked, if they believe that opposition comes mainly from the same people who think that Barack Obama was secretly born in Kenya; they know there's a lunatic fringe (on both sides) and understand the fringe won't defeat them. But they're living in a world of uncertainty. Does this handful of very angry citizens mean that there's a much larger cohort ready to turn against them? Or is it just a lunatic fringe? So the fight is on among activists to try to shape the perceptions of Members of Congress. And that's why activists are going to be so upset when reporters call it against them.
Of course, it's also true that some of the actors involved may believe a lot of the hype that I talked about in the previous post -- that winning or losing a couple days' worth of news cycles will determine the fate of the presidency, the next generation of American politics, and the Republic. None of those things are true. But the fight to get inside the heads of easily frightened Members of Congress is in fact a real fight with real consequences for the health care bill.