There are two theories:
1) The Democrat anger at Bush, much famed at sites such as Smirking Chimp and Daily Kos, is motivated mainly by the overt nature of Bush's strategies of class warfare and imperialism. The Demos are angry because GW Bush is doing things that previous presidents (incl. Clinton) would have done anyway, yet with Bush there is so much in-your-face style to it, so much crass "my way or the highway" posturing, when compared with previous Presidents, including Bush Senior and Reagan. So the Democrat criticism of Bush is an inflammation brought on by his style, without regard to his actual substance. And he's a winner, which makes them jealous.
What adds insult to injury in this regard is that the Demo politicians have been caught without any backbone, as the conversation at Daily Kos seems to have revealed. The elites in DC appear to have conceded any shred of Federal Government leadership they might have had even despite 2002's election having established Repub control of both Houses of Congress, and this leaves the rank and file in a rather undignified position, having been caught believing in political positions (like "oppose Bush") that few people in DC support anymore. So, the reasoning goes, they blame Bush, Nader, any target ready-to-hand.
2) Some of the Demos may have begun to "recognize," or claim to recognize, the US as an imperialist nation run by rich advocates of class warfare, that the government is merely a subsidiary of owning corporations, and that world society is threatened a collapse that is aided and abetted by the course of action proposed daily by the elites. How much of this reality they recognize will vary from Democrat to Democrat. At any rate, Democrat understanding of the global realities of life will be difficult to measure, mostly because they cling to an association with a political party that has left them, partly because they've decided to censor themselves out of fear that they will be lumped in with the Dixie Chicks as "unpatriotic."
Which theory is a better description of the Democrats? What do you think? Respond by Emailing me or contributing to the Ecosocialism blog.