By declaring that he was far too liberal, while lifting and enlarging his nativist themes. That’s a pretty easy lift for a GOP which already hated immigrants before Trump rode into town. That approach mollifies a significant number of his followers, and most of them are going to be denying they ever supported Trump in the first place by December. That will be enough for them to limp along until the next election cycle.
One thing republicans really don’t like, is losing. Yes, McCain has stayed on the national scene, but his popularity has been in steady decline in AZ since 2008. Romney keeps making appearances, but nobody in the base is attending. Dole…well, when he showed up at Congress they went out of their way to embarrass him over the disabilities legislation. And Trump is going to lose by much bigger margins.
The bigger long term problems facing the GOP have to do with A)the complete intellectual void that occupies the conservative arena right now…and has for about 30 years and B) the internal paradoxes to their “principles” cannot stand the test of time.
For instance…you cannot preach that all government is bad…and expect people in government to win people’s votes. They have reached the point in that particular theme, where the theme is out of their hands, and even trying to change it is immediately met with cries of selling out/establishment whores. Perhaps more importantly, they have nothing to replace it with. There are quite literally no new ideas on the right…every single one of the 17…with the possible exception of Paul…was running on the standard Reagan fare…cut taxes, big military, social wedge issue de jour.