First I wanna ask, why?
I can only think of two suggestions;
TuPac - He's got alot of down with whitey/the man stuff. Not that I'm saying he's racist, he just had some issues with white people.
Immortal Technique - You have Dead Prez on your list so you probably know of him but in case you don't his music seems perfect for what you want. Just be warned some of his ideas are pretty out there, they border on paranoid and some would say he's just crazy. Example, He believes the falling of the twin towers was controlled explosives set by the US government.
If you believe that too forgive my
I just don't buy it. Besides that though he's got some good lyrics and he's a smart guy.
If I think of anymore I'll post them, hopefully those helped.