

They could but with FPTP it’d be somewhat self defeating. Generally safer to run with the Dems for the most part, though if you are in a state with RCV or even jungle primaries you should definitely go for it. But as of right now the better strategy on the national level is to pull the same thing the tea party and MAGA did to the Republicans.

By establishment I think they mean old/non trump based Republicans, the ones who will probably still be there once the Trump dies and the cult implodes. While Trump is certainly the establishment more or less at this point there isn’t a much better term for that lot.