Nate Silver plucks out this data point:
Among 38 incumbent congressmen in races rated as "toss-up" or "lean" by Swing State Project, just 8 voted for the bailout as opposed to 30 against: a batting average of .211.
By comparison, the vote among congressmen who don’t have as much to worry about was essentially even: 197 for, 198 against.
In the end, they were worried about re-election.
The Dish 