If Hillary gets the nod from the ASP, which isn't at all a certainty, anyone even slightly to the right of Mao could be elected President in a backlash vote.

It will not be John McCain, since being the GOP nominee will be a requirement. Newt has a far better chance of getting and keeping support from both libertarians and conservatives than does McCain. Both have name recognition--as does Rudy.
President Reagan summed it up nicely, "Some people go through their entire lives wondering if they made a difference, Marines don't have that problem!!!"