In what way?
I think it would be the end of the GOP. GOP Candidates move to the right during primary season and Demos move to the left; and then when they get the nomination they move to the center. That means rudy would be moving even further leftward.
Once he shuts out the right from participation or enfranchisement, the rift would be complete: no more GOP as we know it, just democrat and democrat lite and maybe a new Conservative party. A similar thing happened to the dominant party several generations ago, and the Whigs were decimated when they moved away from their core conservative values & the republican party came into being.
Personally, I’m of the opinion that a Hillary presidency would not be as big of a threat to conservatives as a Rudy presidency.
Why?
With Hillary, Republicans and conservatives have a common enemy. If Republicans manage to regain control of Congress during a Hildabeast presidency, you can BET that they’ll fight against her liberal agenda.
With Rudy, not only will his left-wing issues obtain support from the liberal Democrats, but Republicans will be less inclined to disagree with him, for fear of being disloyal to the Republican Party. And where will this leave the GOP's conservative wing? Not in a good place, I'll tell you that much.