High Black voter turnout hurt gay marriage.
(As an aside, my stance on gay marriage can be quickly summed up by "who cares?". I don't think the state should have any standing in any contract between two people other than to deal with violations of that contract. My marriage is between my wife and me, I don't see why I need permission from the goverment to enter into that contract. If my neighbors Jim and Mark want to get married, I certainly don't care one way or the other. Of course, this issue is exacerbated due to government welfare programs, primarily Social Security, where marriage has a benefit.)