For starters, coming out in support of gay marriage isn't "conducive to advantage or interest," otherwise known as expedient, in an election year. Every liberal pundit I tuned into last night expressed their concern about the decision, fretting that it will cost Obama votes on election day. Republican pundits, politicians and talk show hosts, on the other hand, are absolutely giddy. Limbaugh claims Obama has declared war on traditional marriage. Speaker Boehner "reiterated his opposition to gay marriage" before breaking out in tears of joy. Candidate Romney deemed the very subject insignificant and tried to get back on his favorite topic: tax cuts for the wealthy.
Neither is Obama's decision disingenuous. He's spent time with families of gay and lesbian service men and women. His staff includes openly gay members, a no-no for Camp Romney. His daughters have friends with same-sex parents. All in all, the decision is not merely for show; it's a reflection of his evolution in thinking that's come from spending time with, rather than shielding himself from, the LGBT community.
What about self-serving? Obama has nothing personally to gain from this decision. According to Wikipedia, only New Mexico has "no specific prohibition or recognition of same-sex marriages or unions," so it's not as if he can expect a bump in any swing states with legislation pending.
Like great presidents before him, Obama made this decision because it's the right thing to do. He's showing leadership at a pivotal time in our country's history -- a time when acceptance that gay and lesbian couples should have the same rights as straight couples is growing exponentially. This decision is all the things flip-flopping isn't. And the fact that it could be a deciding factor in this fall's election makes it all the more laudable, noble and risky.