I can only speak from my only experience as a Black American (technically, Haitian American), but bigotry is nothing new with Black people. Both of my parents are native Haitian, but I have Mexican relatives on my father's side. I was born and grew up in Brooklyn, but moved to Long Island when I was young. There was a lot of insults said my way from Black kids growing up for hanging out or going to school with white kids. Compared to Brooklyn, Long Island is the wealthy, white-picket fence community. I started dating Latino and White women during high school, and got a lot of flack from Black men and women for "selling out." Doubly so for being a Haitian, since we were colonized by the French.
As some people have mentioned here already, a lot of people tend to project liberal values onto the Black community. In my own experiences, I have seen Black Americans hold more bigoted and homophobic views than one might think. Even going to two universities in Florida (USF and UF), a lot of Black women held distrust toward men who dated White. As if they weren't good enough, or that they sold out, or didn't acknowledge their own race and history.
As for Obama, I personally in part believe that he couldn't have gotten elected in Chicago had he married a White woman. People might have looked at him as a "well-to-do" Black American that didn't have roots in the community, and marrying a White woman would have further complicated Obama trying to identify as Black even though he has a beautiful mixed legacy. I'd be lying if I said I didn't feel personally resentful toward lighter-skinned Black Americans like Obama compared to darker-skinned ones like myself, since I found they were treated much more favorably by women, law enforcement, teachers, employment, etc. That's just my two cents, though. Obama and Michelle are an amazing couple, race or not.