Racism is indeed not limited to feelings of superiority or hatred: it's making judgements about people's character, qualifications, etc. based exclusively or even primarily on the way they signify racially.

I say "signify" because race is not an objective category, but a socially constructed category. Obama is just as much a white guy as he is a black guy. However because he "looks" "black" he is therefore "black."

Ferraro implied much more than that he gets support because of his race (this much is true). She implied that this is the only quality he has, and the only REAL reason people support him, and she has said explicitly that he wouldn't have gotten as far had he not been black. These are all extremely dicey (and demeaning) propositions.