I disagree with you on both sides of this claim, which you seem to take as proven fact. The ABB attempt was sabotaged by the DP, who shitcanned Howard Dean for being slightly unpredictable and mildly principled and at least verbally against the war. If ABB had worked, I'd be going to Washington to rally for an immediate U.S. withdrawal.
Meanwhile, your attendance at this rally will give aid and comfort to the very ABB nonsense you claim to hate. The logic of the rally, to the extent there is any, is the demand "ABB!" Other than that, 98 percent of the population will just see it as sour grapes. Bush won, Kerry lost. What the hell are you protesting?