Those are extremists. Those are the ones that preach death to all whites and the ones in the bunkers hoping for death to all Blacks. Neither have the power to move the masses unless the masses actually agree with them but are less committed.
I don't discount your passion nor your feelings here.
Personally I find those you mention—in the context of the racial matter—to be the true extremes. However, and i think you may agree with me, they are not the only ones who contribute to the hate necessary for a true race war to develop. No, I suspect that if we move from both extremes slightly more towards the centre, we will find the partisans who—deep down—really would like to see this situation get out of hand as well. I also feel this includes our collective who, time and time again, have proven they are not about distorting facts to get us and them—them and us—really pissed at each other. They profit from it.