Interesting...
Multiple things which haven't been mentioned, but if we're disussing race and racism issues the whole picture is probably necessary. For example, a white man calls a black man subhuman because of the colour of his skin. This is racist. A black man calls a white man subhuman because of the colour of his kin. This is racist. A black man calls another black man subhuman because his skin isn't quite as dark as his. In Malawui, there are crimes we would class as being race crimes between two people from different ancestral tribes, based on skin colour and geographic location. It's racism, but not as we know it.
Also, would everybody stop saying 'we'. I have never once been involved in the owning of slaves, the subjugation of anyone of another skin colour, and I find it ridiculous and insulting to even suggest this to me. By even saying 'we white people need to accept our history of racism' lowers the argument to an unarguable basis. My history does not involve racism. My ancestors' history may or may not (I honestly don't know), but mine doesn't. I don't even see why I have to acknowledge my ancestor's history; as has been said before, I wasn't there.