> All of the checks and balances are kind of predicated on the idea that each arm of government who actually bother to protect their own powers, and use those powers to rein in misbehaviour of the other branches.

I mean, sure, that's the Schoolhouse Rock version. But I'm talking about something else: The executive branch is the branch that controls military, FBI, CIA, BATF, US Marshals - the law enforcement agencies with guns, tanks and planes. Congress and the Courts don't have any similar enforcers. In a showdown where the courts order the executive branch to do something the executive branch can just ignore the order and continue doing what they want. The fact that this hasn't generally happened much in our history is because the executive generally had some kind of respect for the constitution and the institutions that it instantiates. If you get an executive who doesn't give a damn about anything other than maintaining their own power there's really no way to get him/her to comply.

> Nixon wasn’t shamed into doing anything, he was threatened with very credible impeachment, and decided that getting out fast on his own two feet, was better than being taken out slow by the ankles via impeachment.

Ok, but wasn't that at least partly due to the shame that he would incur if he had been impeached? He was afraid of history's judgement - though it was a bit too late for that. In other words, on some level he didn't want the impeachment stain - at a certain level he cared (again, he should've cared earlier, but he thought he was going to get away with it). Now we have a guy who has been impeached twice and he knows he's got enough toadies in the senate so that he won't ever be convicted. Even if the House goes to the Dems in '28 he's not afraid of the threat of impeachment that would likely entail. Nor does he feel any shame over any potential impeachment.