Josh Marshall explains why it matters that Republicans (all the way up to the president) call the Democratic Party the "Democrat Party." Marshall doesn't quite say it, but this behavior is of a piece with Bush's habit of giving everyone a nickname, a dominance strategy practiced by playground bullies, fraternity hazers, and drill sergeants alike: I get to decide what you're called.

Addenda: Useful rundown of Bush's slurs here. Favorite comment from the WSJ blog linked above: "Let’s be fair: It is the Democratic Party. It is the Republican Party. Can’t we all get along? Must we disabuse the language?"