At what point do the Repug congressmen and senators say "enough is enough we can't let you destroy our 250 year democratic system"? Is there even such a point?
If it does happen, I thing the elected GoP officials are more complicit than trump.
They have been complicit.
For many of them, they know that they could make many of the changes Trump wants legally, but that would involve having to negotiate and maybe not getting all of it and also people would be able to point to them and blame them if unhappy.
Much better to hand over their power, let Trump attack the things they want removed, and just assume Trump will give them their power and authority back once he's done doing the stuff they all want.
Lots of them aren't particularly attached to the idea of a democratic system.
The prediction several years ago was simple -- If conservatives become convinced they cannot win democratically, they will not abandon conservatism.
They will abandon democracy. "
There are a handful of old-school GOP floating around who might finally think enough is enough, but they are outnumbered and most won't have the courage to actually switch sides or go independent and vote meaningfully.