The Democrats have painted themselves into a corner with healthcare - they're almost certainly going to suffer electorally in November whichever way the healthcare saga plays out.
Just about everyone here is in agreement that the country is better off if the bill fails.
Which outcome hurts the Democrats/helps the Republicans more - the passage of the bill or its defeat?
The bill passes
Liberals are mostly happy, though a significant portion is upset because it's far short of what they envisioned on election night 2008. The outcome will not affect their votes
Moderates and conservatives, who according to the polls are strongly opposed to the bill, are outraged. They will be highly motivated to give, work, and turn out in November.
The bill doesn't pass
Liberals are outraged. They were promised a healthcare revolution and didn't even get what they think of as a modest compromise.
Conservatives will not be mollified in the least, and will probably be energized by the victory.
Moderates will be disappointed that the modest reforms that they thought they were voting for in 2008 didn't come to pass, and will blame both parties