The Republican leadership ultimately talked Nixon into resigning. They knew it was a lost cause. Here is Dole's eulogy at Nixon's funeral: YouTube Link
The smartest man to ever sit in that office, and yes, I include Thomas Jefferson. Ask any old DC hand.
Nixon favored GHWB for the 1988 nomination, not Dole. He appointed both GHWB and Dole to head the RNC for short stints in the early 1970s. If Nixon were still around, would he probably be backing Mrs. Bill even though she worked on his pending impeachment?
No, the Republican leadership told Nixon they wouldn't protect him in the Senate.
Unlike the Democrats who protected Clinton, no matter what -- the Republicans put the rule of law above the party.