The man, unlike many African-Americans, is truly one half African and one half "white". (I used to wonder about this designation when I was a kid because I'm not "white", I'm pinky-tanny-freckledy. Most "black" people I know are not "black", they are toasty brown.) Anyway, so what if Obama is one half "black"...he's also one half "white". Rejected by his African father, he was raised by a white mother and white grandparents. I think they did pretty well by him, raising-wise.

Which is to say, those same white people who hate him for being black, must hate themselves in equal parts. We all came from the same woman, found buried in sub-Saharan Africa. Anthropologists call her "Eve" because she is literally the mother of us all. Undoubtedly, she must be somewhat black, since the sun in that part of the world caused that evolutionary adaptation.
Blood should mean nothing to any of us. Half my nieces and nephews are adopted and they are every shade of the rainbow except "yellow", that skin-tone representated by Asians. Sadly, we have no Asians in my family. But our family is enriched by the niece who is half Hispanic/half white who has two children who are half Black/one quarter Hispanic/one quarter white. And the half black/half white nephew. And the three-quarter Native American/one quarter white niece. And the "who knows what" niece, who is the most loving, funniest, prettiest niece you'd ever want to have.
And yet, they are my Blood.
I'm reminded of the climax on the musical "Showboat"...a "mulatto" lady who is one 16th black is accused of being married to a white guy. (Inter-racial marriage being a big no-no in that time and place.) In the presence of several witnesses, the husband pricks her finger, sucks the blood and later, when the sheriff comes to call, he swears, along with witnesses, that he has "Negro" blood in him as well.
Blood is blood is blood. Black people's bodies don't reject donor's blood from someome white. Red blood cells, plasma, white blood cells, all are the same regardless of the race. White people who need kidney transplants (I hope) don't refuse a kidney donation simply because it comes from a Hispanic.
I think, in another several generations, we'll all be a nice tanny/toasty brown. And won't it be grand!