How do you think we got the Patriot Act? "pretty soon the people who knocked down these buildings will hear us" "mission accomplished", "evil doers", "mushroom cloud", "nucular". Bush was defended and made excuses for for years.
More to the point, they defended his idea of Presidential power, they defended his use of torture, they defended his failures over and over again, the way he handled news of 9/11, the way he handled Katrina. They even stated that we should never EVER take issue with our commander in chief in a time of war (but had no problem criticizing THIS commander in chief during the same wars). They defended his unitary executive actions and his presidential signing statements. They defended each and everything he did even though, when this next president took office, when this president did the same things, they either grew silent, or objected - to the same sorts of actions.
There were many who actually held to the notion that we really have a 4 year king, and if we didn't like what he did, we should simply shut our mouths about it and vote him out of office if we didn't like what he was doing.
These people believed in almost unbounded presidential power and did everything they could to encourage or hurry that power along. Now they reap what they have sown. Oh they might not have fallen victim to Bush's charisma quite so throughly but they even had a name for us "Bush derangement syndrome". Some of us still suffer from that disease. Only now there is "Obama derangement syndrome" where nothing, no matter what, no matter how, that Obama does, is, intends, thinks or says can possibly be right. Given that, given that absolute hatred of the man, is it any wonder that some of us will go out of our way to defend him? The guy simply can not be as bad as so many paint him and so we feel we must counteract some of that venom.
The hard left hated him and thought he was stupid and incompetent while at the same time they were certain that he had a cruel, sly agenda that he was forwarding with his every action, and the right defended each and every action, even Medicare part D.