You assume that the Republican congressmen actually WANT to oppose the Democrats, but fail to do so out of lack of courage.
I assume the Republican congressmen are in bed with the Democrats. I assume they only pretend to oppose the Dems, in order to win election in conservative districts. I assume their having a deal with the Dems, such that they can engage in graft and have sex with lobbyist women all they want, as long as they don't oppose the Dems in any important ways.
Given the above assumptions, the behavior of the Republican Establishment makes perfect sense, and also explains why they get so hysterical at the idea of some outsider coming in, who is not part of their network of deals.
Oh, I intimately am aware of their duplicity and I hold no opinion they actually care about anyone but themselves.
I’ve said here before many, many times that the Republicans and pundits are the “loyal-but-not-too-vocal-opposition” firmly entrenched in their joy of feathered second tier beds. I’ve also said I’d rather see their traitorous house of cards burn to the ground before I let my vote go to continue any part of it.
They are comfortable with second-tier power as long as they can have their stashed-millions, their dachas and their pink parachute retirements. They are all Vichy traitors, IMO.