I would just have to quibble over your emphasis on ideology. Sometimes it's simpler than that, when an office-holder's actions or beliefs violate one's moral or ethical standards. When your gut says "the bastard's gotta go".

Many of the people who oppose Bush do so not out of some abstract ideology, but because they simply think he's wrong. It offends my moral sense to see Bush turn America into an agressor on a shifting set of flimsy pretexts. It offends my principles to see Bush repudiating or distorting science in service of his ideology. I'm disgusted by the blatant cronyism that rewards Halliburton with lucrative no-bid contracts. Bush's belief in his own divine infallibility makes the hairs on the back of my neck stand up (is Bush President or Pope?). And my intellect tells me that his various strategic decisions, notably Iraq, are simply stupid and have made us all less safe.

Go back a few years, and ask what fundamental political ideological principle fueled the Right's outrage over Clinton's sexual misbehavior. Anything? Or was it simply gut revulsion?

No need to drag in ideology to complicate things. Sometimes you can just trust your instincts. The bastard's gotta go.