> races don't exist

Do they exist in a scientifically viable way?

Most of the definitions around race are tied to a subjective view of a person’s physical appearance.

Is Obama (the son of a black Kenyan man and a white American woman) black or white? If neither, what is this new race to be called? Would he be a different race if his father was also mixed race?

I find that often times asking people this question leads us back to something akin to the one-drop rule and I don’t see any value in that.