Religious intolerance and recial intolerance are two different things. The latter can cause people of the same background to kill each other.

If you want racism to stop, then a pattern of assimilation has to be set and adhered to. Because we tend to recognize people's American citizenship on par with their ethnic heritage, we have more or less made this pattern impossible because we're rcognizing difference in the culture. We're not going to eliminate racism without eliminating difference (which means we'd find other ways to differentiate and hate each other, I suppose). The best you can hope for in a mult-ethnic society like ours is tolerance, for anything and everything. I know people who are closet racists, verbally, at least. As long as they don't do anything to harm or impede someone, though, then so what? That might be as close to acceptance as we'll get for awhile, from some people, at least.