Beats me. Of course, they do want to irritate Bush as much as possible, and if they can suggest that the election wasn't clean, so much the better. But it strikes me as a dangerous game for Dems to play: if they really do stir up a demand for clean elections (e.g., proof of residence to register, picture ID to vote, carefully regulated absentee ballots, etc.), they'll be the losers -- literally, in election after election. Unless, of course, like the preternaturally innocent DUers, they really think the bulk of election fraud is on the Repub side.
And, what about the vote in the State of Washigton, where the dims stole big time.