Barack Obama was born to a white American mother and a black African father. He was thus biracial, coming from a mixed-race heritage. Society, rightly or wrongly, has historically identified biracial (black-white) children as black. This goes back to the old segregationist laws of several hundred years ago, when even one drop of "negro" blood relegated you to a lesser status in society; light-skinned blacks would therefore try to "pass" for white so that they would be treated better and become eligible for better schools and careers. These days, there are more mixed-race couples (inter-racial marriages were illegal in some states until the mid 1960s), so there are more biracial children being born. Mr. Obama has never denied the white side of his family-- in fact, it was his white grandparents who raised him. But because he has African-American features, the culture continues to regard him as black.