Harry Reid is a light-skinned man with no negro dialect.
He's also 70 years old. He was 23 years old when Dr. Martin Luther King, Jr. gave his famous "I have a dream" speech. Reid may have made a mistake by using the word "negro", but he was in no way saying that Obama is a better person, politician, or president because of light-skin and negro-free dialect, nor was he saying that he personally supported Obama because of his skintone and speech patterns.
He was saying that racism is still a powerful force in America, and that an habitual AAVE-speaker could not have been elected President in 2008. Reid's phrasing is a product of his age and culture, just like everyone else's.
Criticizing Reid's phraseology is a bit hypocritical here, much like criticism of negro dialect. Old man, please.