Fish in a barrel

[Lilith7]

Harry Potter - mudbloods. Possibly where they nicked this from although as Harm_less said the idiotic idea of people having 'pure blood' was also used by the Nazis & present day white supremacist's.

These days though only people who don't know anything about the human species, or do but prefer to ignore it, tend to make such daft claims.
I always find it hilarious when one of the white supremacists has a DNA test & discovers that they've got black ancestors, but I think they've probably stopped having them done now. Probably heard the rest of us pissing ourselves laughing...