Rubio is a very possible nominee. He’ll beat Christie as much more appealing to the base. The only possible contenders besides Rubio are: Paul Ryan, Scott Walker, Kasich (who’s blowing it right now with the Medicare implementation), or Jindal. Jeb Bush is a possibility, but I doubt Rubio and Bush would both get in the race. They go way back. If Jeb is running, Rubio would probably defer and endorse. I feel like Rubio would out do most of those guys as a much stronger and more dynamic person.
I can’t think of any other likely nominees, outside of that list. I like all of the above on the list (although do not want any more Bushes in the White House).
Mike Pence? Ted Cruz?