How is supporting marriage equality seen as an election winning strategy?

[agentS]

6. It'll win some votes- not a big number but some.

Some independents who are gay or gay-friendly will remember this- assuming they forgot about the whole DADT repeal already.
Some gays who were angry at the admin for some reason or another will likely change their mind and might vote for him.

the Firebaggers will hate the president and love Grover Norquest so it won't matter. They probably think RMoney is better anyway.
Same goes for the libertarians- even those that think government shouldn't be in the bedroom- they won't change their vote because they'll hate him for some other reason.

Some Democratic party-leaning youth may be more motivated to vote now if they weren't before (re: student loan interest rates).
But he won't get any votes from social conservatives- unless they're motivated by hating Mormons more or have a gay kid, or pure economics.

I'm guessing a lean positive vote.