It's satire, and it reflects poorly on the rednecks singing along, not on Cohen. Recally also that the Borat character got a conservative christian House candidate to concede that the Republican party is the party of Jesus and to admit that he thinks that all Jews go to hell. They guy looked like an ass.
Ali G is one of the most creative shows on TV, and it is biting and novel precisely because he does skits like this one. Is this any different than Dave Chapelle's "Black White Supremacist"?