Before Trump came along, I thought so too. Now I'm not so sure. Maybe the infestation and rot implicates 10-20% of the membership, which happens to be in control. Tear out that wing.
Hindsight being 20-20, I can't now think of any other way to get this political realignment done quickly and relatively neatly. It hinges on an exceptionally strong, confident and well-known person, from outside of the usual political circles - I think the last time this sort of person obtained political visibility and power was colonial America.
I hope you are right. I think we will know by November.