Primary elections are base elections, and Trump’s support among the base is about the highest that any sitting president has had. A primary against him would be an exercise in futility.
I remember our own Free Republic 2015-2016 primary war with fondness... ;-)
It would be a good thing, it would let us see who should never again be in any position of power within the party.
I’d think a Bill Weld with a couple hundred million dollars of deep state advertising money could garner a solid 22% of the R primary votes. So it would be a nice economic boost for consultants and tv advertising.