The longer more candidates stay in the race, and the longer it takes the media to figure out which candidate’s success comes at the direct expense of another, the more time Rubio and Fiorina have to present themselves unobstructed. Until someone is declared their definite rival, their biggest enemy is the unforced error, a gaffe or an ethical scandal.

Now, simply being a great presenter is not the only ingredient for success. In 2008, Mike Huckabee took himself from an obscure governorship to a legitimate challenger and media figure. His electrifying speech at the 2007 Values Voters Summit prevented the leaders of that organization from uniting behind Mitt Romney. But he was eventually eclipsed by John McCain and Romney, neither of whom were then exceptional on the debate stage. He was also exposed to sustained attack in the conservative press for his deviations from party orthodoxy and scandals as governor.

Rubio and Fiorina have no such deviations. So here’s my advice to all the traders on PaddyPower.com: Bet on a sustained rise for both of them until the field is winnowed down, or some bit of damaging opposition research is leaked to the press. They will face determined opposition eventually. But not yet.