I have a feeling that health care reform will fail tomorrow.
No matter what you do, your re-election chances are highly damaged. So let's look long term. A House Democrat who votes "yes" is essentially betting his future reputation that a crap bill, a crap process, and all of the bribes, kickbacks, payoffs, and b***s*** is going to turn up smelling like roses someday. What are the odds of that happening?
On the other hand, Pelosi, Obama, and Reid are desperate to pass some kind of bill. If the current health care bill fails, they're almost certainly going to offer a scaled back "Plan B" to Congress before November. Imagine voting "no" on the health care bill from hell and then voting "yes" on a later, more modest "Plan B" bill for political cover. To me, that sounds like a pretty good deal for an undecided Democrat.
Of course, Pelosi, Obama, and Reid know this, which is why they've been making the "unholy doughnut" argument all year: "You're already going to hell. You might as well take the last bite of the unholy doughnut before you burn."