There isn't much he could do on it even if it was a priority for him because he has Congress and state governments to deal with AND he has to win re-election. I doubt in my lifetime, Florida or Ohio pass gay marriage if it remains a state issue. He has win them to be re-elected which is why I wish he would've waited. I don't think this issue alone is a dealbreaker, but it gives more ammo to Republicans to paint Obama as too left-wing for the people or whatever.
Sometimes, I feel like Obama doesn't want to win. He seems so downtrodden, it worries me. I think he's done a lot or tried to do a lot with the Congress he has to work with.