For a conservative to say he will never vote for Trump does not actually accomplish anything conservative, or even democratic, other than declaring the moral superiority of the NeverTrumper.
Which is the whole point, just like liberals virtue signalling on, say, global warming is all about telegraphing how righteous liberals are.
NeverTrumpers think they are more ideologically pure, or, more likely, just classier.
Donald Trump may turn out to be a great president, or a mediocre one, or a disastrous one. We don’t know yet.
But we do know what Clinton will be like:
Selling foreign policy to the highest bidder; turning non-partisan institutions into political weapons for her family’s interests; continuing her foreign policy failures from Russia to Iraq to North Korea.
You can’t name a single issue where Clinton is better than Trump, but for the NeverTrump’s, this isn’t about high-minded principles.
It's about the “cool kids” wanting to keep their invitations to appear on CNN, and all the fancy dinner parties.