I think Michael Demmons at Balloon Juice asks a fair question about Obama's silence on Prop 8: If Obama won't stand up now, why is there any reason to believe he would be any more receptive to marriage equality if he gets in office or that he would stick his neck out on any other issue?
Of course, Obama has long maintained an opposition to gay marriage, based on his religious beliefs, even as he supports civil unions. He came out against Prop 8 a long time ago, but he has remained pretty silent since. So supporters of marriage rights could reasonably ask whether it's worth voting for someone who isn't showing much courage on an issue of importance to them. The purpose of electing a progressive as president isn't just to have a progressive as president, but rather to have someone who is open to progressive policy goals.
Obama's own tortured logic on gay marriage doesn't exactly make for a compelling counter argument: "I'm against gay marriage, but you should vote against this ballot measure that says gay people can't get married." But that doesn't mean he should remain silent. I also remain perplexed as to why anyone would care enough to prevent consenting adults who want to marry each other from doing so.
--A. Serwer