I think a reader sums it up pretty well for Nancy Pelosi’s caucus:

Obama Care is like a hot potato. First Pelosi crafts a highly complex, and almost impossible bill to understand. She passes the monstrosity to Reid, who in turn makes it even worse. Both leaders had to resort to bribes and strong arm tactics to get it passed. Pelosi was so desperate that she allowed restrictive abortion language to be inserted to get the necessary votes. Now with the election of Scott Brown the hot potato is back in her court. And now the pressure to get it passed just got notched up a bit. And I’m sure she doesn’t want to be the one who gets the blame for its non-passage. The bill cannot be allowed to go back to the Senate, and the Obama White House has moved on.
What is so amazing about this entire farce was the insistence by President Obama to get it passed immediately. Remember the deadlines? August of 2009 was moved to September. Then people were talking about Christmas and New Years. Finally, the deadline was moved to the State of the Union. But each step of the way lurked the President -He had to have his health care bill NOW!. But now the President conveniently has held Senator Reid and Pelosi out to dry. The House Speaker is on her own. Suddenly, the folks at the Daily Kos and Huffington have the delusion that she can simply snap her fingers and reconcile this thing. All the while they ignore the fact that last autumn she was only just able to come up with the needed votes for passage. Madame Speaker has no room for error (3 votes). Somehow the Speaker is to do what couldn’t be done last year. Of course the GOP has no incentive to assist her, this being an election year. And yesterday’s election of Scott Brown must send shivers up the spines of dozens of Blue Dogs. I’m sure there are many of them who are wondering why they should be the ones to risk their professional careers.
I’m sure the Speaker would just love to declare defeat, move on and hope that the job situation improves enough to allow her party to retain its majority and her her job. The longer this bill remains on the table, the worse off her party will be. The idea of beginning again from scratch is anathema to her base.. But to be asked to walk the plank and pull reconciliation would be a political disaster I don’t think even the most motivated Leftist wants to think about. The best thing for the Dems is to call it quits and find a bogeyman to attack (Fat Cat bankers), hope that the jobs situation improves before election day.