This is not a two man race.
You should hope it is. In the end it will come down to voting on obama's record. He will counter that he's gained valuable experience and in foreign policy has killed off the leadership of the terrorists and helped begin the democratic process in the middle east.
If we have a nominee with no executive experience we lose that card. If the SCOTUS rules the healthcare personal mandate is unconstitutional, but leaves the rest of the law in place we lose that card.
The two candidates that have executive experience as Gov's are Perry and Romney. It will come down to them.