Blacks that are actually from Africa sometimes see American blacks as inferior partly because they aren't "pure" but generally have some white admixture. I had a black speech instructor in college (funny story on its own), and she told the class that the only time she'd ever been called the N word to her face was from a black African.
Those types who believe that way wouldn't consider Obama to be black at all, because of how pale he is and his half white admixture.
There are American blacks who feel that way too of course, but perhaps to a lesser degree.