It assumes that only voters who aren't African-American use logic, reasoning and rational thought before reaching a conclusion.
I'm sorry, but a group of voters who self identify by race and vote 95% for a party that continually undermines their individual pursuit of happiness, aren't applying logic and reason when voting.
Colin Powell voted for Obama.
Think he did that with his head, or with while looking into a mirror.
Your subject-verb disagreement gets to the issue here. Groups don't apply logic, individuals do.