The subject line asks a very good question. The answer? Well, it is quite likely that Americans have had it with liberal Democrats and are even starting to return support to incumbent Republicans that were looking doom right in the face.
Case in point? How about John Sununu??? Most polls have him getting clobbered by former Governor Jeanne Shaheen in New Hampshire. According to CQ Politics, the tables are starting to turn though as a new American Research Group poll shows that the incumbent Republican senator has made up some ground and now leads the race 52 - 41.
If Democrats were expecting to face a demoralized Republican base going in to the 2008 election cycle, they are sadly mistaken. As we saw with the OH-05 special election, Republicans are still getting out the vote and supporting conservative candidates.
UPDATE: Need further evidence? Compare Congressional approval ratings with that of President Bush...
UPDATE 2: If Democrats aren't running scared, then why are the freshmen padding their independence?