This is good two ways:
- He supports gay marriage. Yay!
- It lends credibility to the general subtle message he tries to send to his liberal supporters, a message that I interpret as "We can have aggressively progressive rhetoric, or I can silently do my absolute best to make a genuinely progressive agenda happen. I'm going to keep my mouth shut and get us some universal healthcare, end DADT, and enact serious consumer protections in the credit markets." I like this plan, since I'd much rather have an effective guy who sounds moderate, but gets progressive stuff done, than a wild-eyed radical that says all the things I think, but is totally ineffective in wrangling congress.