I think that starting out with “acceptably black” would’ve been more on target (instead of emphasizing that he’s a “mixed-race man”).
Acceptably black means being nonthreatening to white people inclined to feeling threatened by black people. It means standard English, clean-cut appearance (or, as Joe Biden fumbled, “clean”) and the most Caucasian features possible. These obviously are not objective measures of character or worth; just as obviously, they are measures of what sells to the vast, white audience. Halle Berry and Denzel Washington are acceptably black. Your local news anchors are acceptably black. Tupac was not.
Source:
http://adage.com/article/ad-review/hardened-racists-vote-barack-obama/122906/