After the Amendment 1- I believe it would hurt. It clearly wouldn't help him inNC and any other state which has voted that way
Amendment One was a low turn out primary election dominated by conservatives and older voters like one would expect. A lot of support for gay marriage is predicated on apathy itself; "why should I care if gays get married?" isn't too far from "why should I care to go vote?". Younger voters are like that, sadly. Most states, like Obama, have "evolving" views on gay marriage. There is no possible situation where Obama would win NC without winning nationwide so that anecdote would be neutral overall. If it extends to states like Ohio it could be a negative but I do not think it would. I also do not think Mittens can win the marriage issue the way W. did considering his statements back in 1994.