If they take the case, all Obama has to do is look sternly at Roberts, and he’ll change sides.
He already changed sides and to my knowledge he has never come back. The chances of this going the direction of sanity are slim given that his lesbian cousin will be in the courtroom.
You are assuming he is on the conservative side to begin with. I think that them stating there is no legal standing to take the case would be the best outcome we could hope for... even if it means CA gets gay marriage. They can have it.
This would be a huge loss for the LGBT, their strategy all along has been to push this to the federal level and force the judicial branch to declare gay marriage a right throughout the land. If this approach fails watch for a military member( ie federal employee ) to sue up to the feds for denial of benefits in state X when they were legally married in state Y. This is not over by a long shot.