I don't see it as an either-or choice. You can be multiracial and be Black, and any other culture you want. I see myself as multiracial, Black and Latina, for example. I think if you WANT to call yourself white you can too, but in most cases white people and others won't accept this. I don't see why a person who is mixed with Polish and Black can't say they are Polish or Black Polish or whatever - if they have a Polish name, speak Polish, know Polish traditions etc. then they are Polish - since when do Poles have to be only white?