That's a tough one. The biggest thing against Obama is the economy. If the Republicans lose that, he'll be really hard to beat. Obama is a full-blooded politician and a lawyer to-boot that's a deadly combination. Thing is, I really don't see the economy getting much better. Unemployment went down last month because of the Christmas rush.
I think we'll find two things next month, 1) the unemployment numbers were exaggerated for the month of December, and 2) January's unemployment numbers will spike back up.
Again, I really don't see things getting any better if Obama holds to the convoluted theory that spending money we don't have will somehow generate jobs or income. Let's see you or I try that one.
For the sake of argument, if the economy gets better he wins against Romney, who will be the nominee, if it stays the same or gets worse - he's gone! If Romney can't pull that off, Republican's deserve to lose.