No, what we get is people like McCain & Jeffords. If the conservative "base" is guaranteed by people who will mindlessly vote for anyone with an 'R' by his name, why shouldn't the party go as hard left as they can to pick up the moderates?
Bush is not a member of the 'conservative' party. He is a Republican in the Republican Party. The reason Rove IS going left fishing for voters is because of the nitwits who stayed home in 2000.