The GOP establishment, which the Federalist Society that now controls the SCOTUS represents, never liked Trump.
They spent decades turning their base into conspiratorial, counterfactual nitwits through the media they own because then they could easily tell them "climate change isnt real! Give rich people all the money! Poor people made bad decisions!" etc, and rob everyone blind to thunderous applause and their nitwits defending the owner's grift from the rest of us.
Then one day a notorious opportunist got up on stage, said the quiet parts out loud, co-opted that engineered willfull ignorance, and stole their nitwit brigade right out from under them. Remember, the turning point for Trump was the day he told the crowd he'd like to take protesters out back and "beat the shit" out of them. Prior to that he was hiring extras to attend his rallies.
The Machiavellian Mitch McConnells and John Roberts have been quietly seething ever since. Trump makes them feel dirty because he embodies the crassness of the con they've been leading their nitwit voters around by from a sterile distance. Their crass nitwits aren't supposed to bleed into their halls of power! Their careful, coordinated long game grift compromised by a 2 bit snake oil song and dance grifter.