I totally see how this could upset people. But I'm not sure how his management qualities are tied to his political opinions. It's the same with politicans, what the fuck has an affair to do with their political views? I 100% support gay marriage. I also understand they're upset. But I don't know if this is the right reaction.
I see a big difference between having an affair, and spending money to whatever the equivalent is (a proposition to end hetero marriages?). The $1000 was a hateful spend.
I'm not sure what social benefit marriage is supposed to confer. If it's to do with raising of children, then clearly only those who have a child should be able to get married. If it's to do with committed relationships being good for society, then anyone in any kind of committed relationship (and not necessarily a sexual one) should be able to get married.
If you can't point to any specific benefit that marriage is supposed to bring to society, then it just looks like the state is trying to control peoples sexuality which is weird, and there's no need for it at all.
If you can point to a specific benefit, then that benefit should be the benchmark for who can and who cannot get married.