A big chunk of Republican “Never Trumpers” are Bush family partisans.
As staff Secretary to President George W. Bush for three years, Kavanaugh handled nearly every piece of paper that touched the President’s desk. He was one of the most important gatekeepers to the President. The whole Bush network worked with Kavanaugh, through many of their most trying times - it must feel like they have been to war together.
Emotionally, they really have to feel that Trump is one of them now. Not only has he promoted one of them to a pinnacle position - he has gone to war on their behalf, and proven himself to be a hero for them.
This has been the kind of political fight that would have sent them fleeing for cover - but General Trump charged into the face of their feared enemy, and won for them.
Winning hearts and minds.
I'm fascinated that a number of NeverTrumpers who call themselves "Republicans" and "conservatives" have effectively outed themselves as Democrats.
Benjamin Wittes, Bill Kristol, Jennifer Rubin, Tom Nichols, Rick Wilson, Steve Schmidt, Ana Navarro, and Nicolle Wallace all came out against Brett Kavanaugh on Twitter.
They're Democrats, and can STFU in the future about being "Republican" or "conservative".