The Democrats have convinced themselves that Bush was never elected. That is what they are using to convince themselves that they are going to win in a landslide.
If you want to see the Democrats defeated, here is the tactical methodology:
http://www.freerepublic.com/focus/news/1631282/posts?page=15
That thread and post 49ish within it lists the districts considered vulnerable. It is there to send money to the GOP candidate and if it's driving distance (or if you're bold, flying distance), go there and volunteer for the campaigns.
The Democrats must not be allowed to take power. The crushing blow delivered to them if they don't in November is one from which they may not survive.