I'd like to add that while support for the march did largely break down along racial lines, there were a few people of color that rabidly denounced us, and many whites who expressed their support strongly. Overall, the best support I saw (I was there Sunday and Monday) came from DC, esp. in the largely minority North East.
This march was a great chance to build a community, and to reach out to people that might not usually come into contact with this kind of protest. This was one reason I was so pleased with the reception we got in DC (from the people, not necessarily the police!)
Thanks to everyone who organized the march, to everyone who helped us out with food, lodging, transport, and all the other towering logistical obstacles, and to everyone who marched, and also to everyone who supported us along the way; I hope they'll be IN the next march!