He finally came out and voiced his support for gay marriage and only needed his vice president and members of his cabinet to already have stated support for it as well as waiting almost a full year since he changed his mind last June. It is sad that Obama decided that he supported gay marriage so long ago but could only be goaded into actually acknowledging it by peer pressure - even then it is fairly sure that if the polls weren't so rapidly shifting in support of it he would have kept his mouth shut.
It is an interesting situation to watch. Even in the past two years national support for gay marriage in the US has skyrocketed from 41 to 49 percent and it is a pretty damn good bet that in 2016 the Democratic candidate will make gay marriage a part of their platform if it doesn't happen in 2012. They might not believe in it personally but they will believe in the polls - politicians are predictable like that.
It is a good thing to see and I hope we see more of this sort of adjustment in future. Opinions on social matters are changing more rapidly now than ever before in history, largely due to the internet I suspect, and since we see a strong trend towards being a more inclusive and tolerant society I figure things will continue to improve faster than ever. There have been bumps and setbacks of course and there will be again but the trend is undeniable. The one thing that really worries me about positive social change is that too much of it may be based on continuing economic improvement. When we are all rich and getting richer it is not so hard to look out for the marginalized people in society but that seems to go by the wayside when times get 'tough'.