The Never Trumpers May Destroy Him. Then What?

Then what?  It doesn’t matter.
Removing Trump from office by any legal means shouldn’t scare anyone.  It’s not like he’s Saddam Hussein and this is Iraq with its Ba’athist Party, in an environment with sects of Muslims that have hated each other’s guts for 1400 years.  He’s a cancer in the United States, and no one worries too much about removing a tumor from an otherwise healthy body.
Worried about stock market volatility?  Don’t be.  Markets like rationality, reason, and predictability.  Trump affords the world precious little of any of that.
Concerned that it will take a long time before the majority of Americans has any respect for or trust in the Republican Party?  Well, that’s is indeed well-founded, but isn’t that a positive thing?  How much good do you think people like Mitch McConnell, William Barr, Jared Kushner, Steven Miller, Steve Bannon, Betsy DeVos, Ben Carson, and Wilbur Ross are doing for our country?
Personally, I don’t care if the GOP never recovers at all, but if it does, it certainly needs a wholesale rethinking of its values and its relationship with the people it ostensibly serves.