I’m surprised this kind of argumentation as mentioned by Christian D. is necessary. Racist jokes tell more about their narrator and his social environment than they do tell about their subject. On the other hand in Poland the national identity is still work in progress. I think, this is due to the awfull history the country has experienced. Thus Polish people are even more sensitive to rasism. That’s why racists feel attracted to them, I suppose. I’m from Poland and I live in Germany since many years.