Sexual attraction is not a logical choice. People become attracted to someone first (or not) and rationalize it after the fact. No one goes, "she's black, therefore I'm choosing to not have a boner."
I agree that sexual attraction is not a logical choice. If you tend not to be attracted to black women, that doesn't mean you're necessarily racist. It could just mean that, statistically, you have had a tendency to not be attracted to black women, and that can be for a variety of reasons, such as lack of black women in your vicinity. However, a lot of people, while not considering themselves racist in general, do in fact automatically rule out being attracted to people of specific races. In other cases, they have a fetish for a particular race. In both cases, that is in fact racist, because a conscious choice has been made on the basis of race. People's conscious choices can, to a degree, influence their tastes.
It's still not racism. Prejudice? Yes. But unless you're believing they're inferior because of their race then you're not being racist. I guess in the layman's version of racism you're being racist (regarding examples 2 and 3), but per the actual definition you're not.
