Well, you called it earlier today: it's an African-American thing.
It is utterly impossible for some conservatives to conceive of the idea that someone thinking for himself could possibly come to a different conclusion than theirs.
Something else must account for it. Race, religion, ethnic group, class (except upper), blood type, something like that.
I find it insulting for Limbaugh to imply that because Colin Powell achieved high rank in the military, he owes allegiance to the political party in power when he got his stars, as if he didn't achieve that himself. Powell knows to whom he owes allegiance: to the country, not to any political party.