Debra Dickerson, author of The End of Blackness: Returning the Souls of Black Folk to Their Rightful Owners, writes in Salon Magazine:
“Black,” in our political and social reality, means those descended from West African slaves. Voluntary immigrants of African descent (even those descended from West Indian slaves) are just that, voluntary immigrants of African descent with markedly different outlooks on the role of race in their lives and in politics. At a minimum, it can’t be assumed that a Nigerian cabdriver and a third-generation Harlemite have more in common than the fact a cop won’t bother to make the distinction. They’re both “black” as a matter of skin color and DNA, but only the Harlemite, for better or worse, is politically and culturally black, as we use the term.
Apparently, Obama not being a descendant of American slaves cannot be “black.” It doesn’t matter that any bigot won’t make that distinction and will discriminate against Obama based on his skin color. What matters to Dickerson is whether Obama’s parents entered America voluntarily. Or maybe even more important to her in discerning Obama’s blackness is his “outlook[...] on the role of race in [...] lives and in politics.”
Watch as Stephen Colbert interviews Dickerson on the Colbert Report. It turns out that Obama isn’t “black”; he’s “African African American.” :roll:
I'm Brent Logan and I've been here since 2004, writing about family, food, and fun. You can contact me at 
Well, I guess they could have accused him of being an Oreo cookie.
I have news for the blacks that think Obama isn’t ‘black’ enough; the country is full of well-educated, mixed-blood, people with a high level of intelligence and a mainstream work ethic. Maybe those who don’t acknowledge that ought to get their head out of the armpit.
I regard statements like the one you quote as being little more than sour grapes. According to that viewpoint, those of black skin who are here because they are fleeing genocide and/or civil war in the country of origin aren’t black either.