Well, Bush never really campaigned as a conservative, for the most part. He was a "compassionate conservative".
It makes no sense to abandon "the GOP" because President Bush has done some things we don't like. He's not the guy up for reelection. What the GOP does nationally shouldn't really matter at all either when you're talking about Congressional races, because your vote should be based on the guys who are on the ballot in the particular races in which you are voting.
For the life of me, I can't figure out why how Arlen Spector or any other RINO votes should affect whether I'm willing to support a particular Republican in a race.
After eight years of Clinton, mad dogs could not keep me from voting. Also, I couldn't live with the shame of putting our troops under direction of a democrat.