McCain and Romney were right wingers? They were pretty much the most liberal pubs out there in those two cycles (except for maybe Huntsman?) and they were the pick of the establishment. Did they cater to the right? Sure, but I think most people would tell you that neither of these guys were believers. They were accepted.
I think we've seen the end of the hard right influence as witnessed by a much more moderate set of senatorial candidates this past year versus in the previous elections, though the house is a different story altogether due to district maps. The dems are doing a great of job of painting pubs as whack jobs…much like how the pubs made liberal a 4 letter word in the 80s.
I fully expect the Republicans will once again nominate the most "moderate" like Jeb over any of the crazies out there. Granted Bush may not be moderate by some people's definition but he's a lot more centrist than Cruz, Huckabee, Santorum, Paul, Palin, etc.