Hard to keep track of who is under cutting Trump, I think just about everybody was at one time or another. Which begs the bigger picture question, why did trump not instill any loyalty amongst those at work closest with him?
I think in part, it was because the establishment political workers saw him as a flash-in-the-pan. Trump was the guy who crashed the DC party and was fun for a few beers, but the hard core party throwers were in DC permanently and Trump wasn’t so they weren’t going to permanently hitch their wagon to him. These people are political prostitutes—they will go wherever the power/jobs/money is and, long-term, they thought it was with other establishment political leaders. They are disloyal by their very nature and will backstab establishment leaders as well. There is a reason Diogenes never came to DC looking for an honest man and why Harry Truman said, “If you want a friend in Washington, get a dog.”.