Personally, I think racial issues are too often far closer to the social class issues mentioned in the article, than economic ones... or even genuine full blown racial hatred. A lot of times, it is more mannerisms -- how someone speaks, how someone dresses -- that seem to be a huge amount of what is described as "racist".

So many times, when you hear racism of any kind, it's more complaints about mannerisms. Stuff like: That black person, dressing up in "gangster" (read: hip-hop fashionable) clothing, playing "gangster" music (also read: general hip-hop), well, to the racist, he must be a "thug". Regardless of how rich or poor that person is, regardless of the actual lack of "thuggery", etc.

Put a similar black person in a business suit, adjust the mannerisms to be more "professional" for a lack of a better term, and the person becomes more acceptable to the "professional" type classes. (However, he might be an "Uncle Tom" to some of his black peers, and he probably won't impress the "blue collar" social class either.)

You can go on from there. I do think there are general "I hate everyone who is xyz race" people out there as well, but I almost would be willing to say that a lot of racism is more the sort of social class issues identified in the article. The race is almost more of a side note as a way people over-generalize, kind of like the "Southern accent = hicks" over-generalization mentioned above.