Some Democrats are complaining already about the President's decision to say that he didn't oppose gay marriage, when you read between the first read lines, even though President Obama's hand pretty much got forced on gay marriage by the North Carolina referendum, in the end.
In a presidential election year, his hemming and hawing on that issue wouldn't survive a vote like that, as to looking indcisive, and Biden made that obvious, probably because that's how he saw it too, if that could be a deal too; who knows these things really at that level.
Why did the Republicans put that issue on the ballot?
Because it brought back fond memories of the same thing in Ohio in 2004, so, what's the percentage in looking waffling at that point really?
At least by making that call now, you can't say that the President doesn't have any willingness to offend people who really don't like him much anyway, something a lot of Democrats have complained about already.
The author by the way hopes that Indian tribes should adopt gay couples so to speak as to Tribal Court jurisdiction, as to the Full Faith and Credit Clause issue going away, but that's a "modest proposal" for another post as to the intrinsic Federal issue raised where there is a convenient and functional anomaly in our legal order as to the Tribes having sovereignty over some matters.
In the final analysis of the President's decision on gay marriage on a more practical level, presumably as to Tribal Court, President Obama has a constituency that cares a lot about that, most of... whom actually are not gay, but just vey socially to the Left on that issue, and in an election year, people like that have to feel like that they aren't being used.
The Republicans have a Base that cares about that too, the latter being why that got put on the ballot where the Democrats are having their convention, and where winning North Carolina seals things for Obama in 2012, just like Ohio in 2004, same strategy.
In the end, the net political effect will obviously be to polarize the electorate, to force people to make choices, which the North Carolina referendum did, which is a good strategy, potentially, unless we need to be ready to crush Iran, North Korea, and then face down Russia and China all at once, because Iran knows Israel is getting ready to strike, and North Korea knows that if Iran goes it's next under the bus, and so, their fates are wedded together.
Then you might want to avoid too much of a food fight, on the theory that atheistic Chinese and non-Orthodox Christians and Idol worshippers per the Kims and crazed Shia Mulsims might be worse enemies than the United States than some homosexuals.
But as to domestic context, as to Democrat whining and Republican gloating, the net effect will clearly hurt Obama in the Deep South, but which he would lose anyway pretty much, if North Carolina hurts, and maybe in places like Ohio and PA too, and Indianna.
On the other hand, he threw a bone to a base that is the mirror image of the Republicans as to really caring about that issue, and so will be more motivated to donate, vote etc.
Who is more motivated will determine the net impact on winning the general election. In the end, if people probably don't really like you that much anyway, and hell will freeze over before Barrack Obama carries Mississippi or Alabama, if he's sad to see North Carolina go, maybe you just live with that ,and then go with your long-term friends, meaning that there were risks for the Republicans in that strategy too, if net it probably makes this year for a closer race, slightly.