The "Democrat" party.

It's official -- it is now the "Democrat" party -- since the WH has its official spokespeople calling it that, as shown in this WaPo story today: "'As we move forward with our efforts to talk about the problem and the need for reform, administration officials are talking about what leaders of the Democrat Party have said about the problem,' White House spokeswoman Claire Buchan said."

They probably like it cause it sounds like "Bureaucrat". And it's insulting, but in a way that no one can quite articulate. And if asked, they can always claim it's all just a slip of the tongue. As though, if Nancy Pelosi started calling them the "Republic" party in official statements, it wouldn't be questioned.

UPDATE:
Kos has a discussion of this here.

Actually, not just a slip of the tongue. Here are two written press release examples of Republican groups using the term:

Texas GOP Press Release, June 2004

New Hampshire Republican State Committee Press Release, April 2004

Everyone else who uses it seems to be an insane right-wing fanatical freak.

I wonder if I can get Bill Safire to do a words column and research the history of this use of the term for me. Ooh, and today was the last day I have to read his annoying op-eds in the Times.