See, I think McCain already knows that he can't win as a Republican. He's been down that road before. I think he changes parties and runs, betting that enough centrist Dems and RINOs are out there to give him the WH.
He might switch parties but he knows he'd be running against a Repub with backing. It would be a fool's play. At this point in time, he'd probably be happy to be an Ambassador. It's over and he knows it...clap your hands!!
The Demodogs on the far left will kill any chance of McCain getting nominated there. Believe it or not, the conservative "scorecards" all rate him highly, and abortion is one of those litmus issues that would derail him. His only real chance of being elected president would be as a third party candidate.