The Way It Works: Bush, Nixon, & Trump

George H.W. Bush was the head of the Republican National Committee when Nixon was going down. From reading Jon Meacham's biography I learn that like all Republicans he defended Nixon (the chief duty of the head of the RNC was to defend the POTUS no matter what) until it was impossible to defend him any longer. It was touch and go in the last few days until Nixon did decide to resign. Bush supported resignation but not until there was no alternative.
It is safe to say that Republicans will continue to defend Trump until they simply can't do it anymore. This is the way it works.