Only two facts that really make a difference. 1) Obama is president. 2) Hillary will beat anybody but Christie, Rubio, Jeb, maybe even Jindal. None of them will get past the evangelical nut jobs that are much more likely to put up a screwball like Huckabee.
Mrs. Clinton willl probably beat Rubio, Jindal, Jeb, or Christie. I can see Mrs. Clinton debating Christie, for example. He willl alienate millions by his confrontational bluster. I don't believe the others would do much better against Mrs. Clinton.