None of the likely candidates for Republican could really beat Obama. Obama's gonna demolish all of them on their rhetoric, and the American people are mostly behind the kind of "class warfare" things that Republicans are opposed to. Americans don't consider Corporations people, they think the Rich should pay more in taxes, they want our wars done away with (Obama got shit from Republicans for the Iraq war coming to some sort of end... according to Bush's timeline), and I think Obama's gonna ride the fact that Republicans have been obstructionists his entire term to re-election. He's going to point to all the things he's doing that he has the legal authority to do (foreign policy, student loans, foreclosure statuses, etc) and say your beef isn't with me, it's with the Republicans in Congress. Romney's flipflopped on too many things, Cain would be destroyed by Obama in any debate, Gingrich said you can't quote him or you're lying, Paul won't get the nomination, Huntsman won't get the nomination, and who's left?
I think the American people will actually hear this argument. If we had a better system in place, I don't know if Obama would get reelected, but he's going to be the lesser of two evils.