That assumes that Dukakis would have won if it hadn't been GHW Bush, an unlikely proposition. It also assumes that Clinton would have won in 1992 against someone other than Bush, an unlikely proposition. It also assumes that even if Gore was running in 2000 as the sitting VP (if Clinton is not Prez then that is not the case), that if you run a real conservative, he would not win. I think that is not true.
The question is a good one; I believe, and have for quite a while, that the Bush family views it as their calling to oversee the leftward move of the US Government in a moderate way, and certainly does not see the New Deal and Great Society as things to be repealed.