Stopping Obama is priority #2.
Nominating any of Santorum, Bachmann, Perry or Gingrich is priority #3 but obviously inextricably entwined with priority #1.
Santorum may well be the best of the remaining non-Romneys. He was a pro-life hero in the Senate. He endorsed Specter for the apparent reasonable reason that the rampagingly pro-abort Specter agreed, in exchange, to stop no pro-life judges as Judiciary Chairman. I believe that Specter made good on that promise. Additionally, Toomey had been a pro-abort during his time as s Congressman but had, Romney-like, "discovered" he was pro-life before taking on Specter on a statewide basis.
In any event, add me to the Santorum ping list.