Most people will not question the idea that black families earn less, on average, than white ones. Democrats use this to advance the idea that discrimination still exists. Star Parker, herself a black woman (to defuse the idea that I am coming up with these ideas all on my own), proposes some alternative reasons why this might be.[1] A much higher percentage of broken families, and a higher percentage of AIDS (which is a behavioral disease remember, you have to be promiscuous or drug using to get it) go a long way to explain things, if you happen to believe, as I do, that the family is the basic building block of a stable and prosperous society.
[1] http://www.townhall.com/columnists/StarParker/sp20050504.shtml