Well, and I am not a Bush-basher by the way, and there are certainly many here who are. But, this needs to be remembered:
The Republicans are politicians too. That means that their primary objective on an individual basis is to stay elected. They therefore have an incentive to please the left, if they know that the right is going to vote for them no matter what. This is why they need to know that we will not vote for them no matter what.