My take:
BO got his Senate position by a freak: Jeri Ryan divorced her husband, Jack Ryan, over his wanting to have sex with her in public places. Jack Ryan resigned from the senate race, and BO ran uncontested. BO was the only other person in the race, and, he's not been around that long. He lies, and changes position like Hillary. He's not a woman, so, he doesn't instantly get the "I want Hillary because I want the first woman president people."
BO, at least according to Rush, Mike Savage, and the other conservative talk show guys, has fairly extensive contact with terrorist muslim leaders. He can't seem to figure out what religion he is, Catholic/Christian or Muslim. Combine that with his anti-gun stance, Chicago's anti-gun stance, his failure to do anything about D.C.'s anti-gun laws, and what he stood for before he had a chance to run for president, and, we never have to get to race.
However, in a pragmatic sense, I would guess that the first black president in the U.S. might be a high risk for assassination, so, his VP has to be very good. That's about as far as race plays into it for me, that the possibility of being a target for a racist is the only real consideration I would give the issue, and, for that reason, I would seriously look at the president and the VP as a package, more then I would with most other candidates.