Somebody is stupid alright, but I'm not sure it's the rest of your country in this case.
Being 'black' is as much a culture as it is a skin colour, because biracial people suffered and suffer the same injustices, racism, and segregation as 'pureblood' black people. And for the record, mulattos are definitely considered 'black' by that culture.
DR, what exactly is your point here? Are you claiming he's not a black president? Because half black is still a lot more than any other president in US history. It just seems like a pretty odd statement, even for you.