It could be a preference, but by stating "No blacks or no Jews," on your profile, I would tend to think it more racist, simply because you are already ruling them out based on their race. I consider a preference something I choose to be a part of, like dating someone who is a Christian. You can't exactly change your race, just like you can't really change your height, so I'm not about to rule someone out based on that.
Okay. Michael Jackson did change his race, but there are always exceptions.
I only know what it is to me: preference. I'm generally not attracted (physically) at all to black or hispanic guys. But of course there are always instances where personality out-weighs physicality. So again, it's just preference to me. I look at it this way: I can't help who I'm attracted to. I tend to believe attraction to be an instinctual thing mostly.
I dunno, i guess it depends.. I mean, I know in practice that i visually prefer white guys over black, and native american over spanish, have no attraction to the middle eastern guys in my area etc etc, but i wont point blank refuse to date someone because of this preference. (my first boyfriend was black/hispanic) I dont think acknowledging this preference makes me racist in any way... Maybe its just easier to say 'no' on the looking for page? Then again, i dont think its much different than saying i wont date someone with kids, or pets, or who is thin/fat/has brown eyes/insert random quality here. You're just stating what youre looking for without the fear of being PC?
Its kind of a touchy subject, isnt it?