Actually, I think I’m wrong about the president having veto power over DC-passed legislation. It seems that congress as a body has veto power over District of Columbia legislation, with no presidential check. If so, that makes it all the more likely that congress could allow same-sex marriage to pass in DC. That in turn would create a same-sex marriage “Mecca” for the country in a way that Massachusetts has not. (Massachusetts has a law preventing it from performing marriages that would not be valid in the home state of out of state residents.) Even so, I seriously doubt that a Democratic congress would allow this issue to come up. But without the possibility of a presidential veto, the opening is there.