Voting for Obama because he's part black would be as stupid as voting for Bush because he was white. By no means is a person a representative of their group who they happen to share skin tone with, that's utterly ridiculous.
Only racist who think in terms of collective race, as in how many presidents or how many scientists how many fill in the blank professionals does race X have? and judges itself by how many people of a certain profession belong to their "group" would think in such a way as to give extension to their entire race based on what one guy does.
Thank goodness that one Chinese guy is in the NBA, they've now been vindicated

....
That's the level of ridiculous we're dealing with here.
People are made to feel inferior by collectivism. I purple guy being president would have no more barring to all purple people than when a purple guy murders someone and goes to jail. The purple people didn't do it, THAT particular purple guy did it. A him achieving or ruining something reflects no more on purple people in general than it would on silver people because none of them did it, the individual did it.