It's easy to whittle down this field to about 5 or 6 people. Bush, Fiorina and Rubio will come out of this pack with Carson bringing up the rear.
Rubio is pretty status quo where Republicanism is concerned...however he came across as a statesman and that will appeal to Republican voters.
I think Carson doesn't have the personality to win this race and will fall to the back eventually. He would be better off jumping on someone else's ticket.
Trump obviously has no shot. Fiorina whether you disagree with her policies is a very strong candidate and will probably be a top two candidate come election time.