They started to hate Bush again after the 2002 elections when they lost seats in congress. I hate to say it, but it might simply be lust for power.
They hate Bush because he didn't allow Gore to steal the election. They thought they had it in the bag, just like Chicago and the 1960 election, when Daly delivered dead voters to the polls, just the number JFK needed to take the state and the presidency. Same play from the playbook in 2000, only this time Bush decided to play hardball and Gore was left with egg on his face and no job.