Bigger picture, a genuine curious question:
For the sake of argument, let's imagine a scenario in which, someday, a ridiculously, blatantly corrupt person became President. And Congress was aware, but had controlling majorities that, one way or another, were aligned with this situation. And the Supreme Court had already been started to be stacked by the same person. And various agencies under Executive branch, which might normally be able to push back, were being systematically gutted, and otherwise intimidated, including blatant reprisal against law enforcement officers for even investigating some past corruption case. And let's imagine that some oligarchs bought up a lot of Fourth Estate, and most of the rest of the Fourth Estate was decimated by other oligarch "disruptive tech", and tech oligarchs also control much of the remaining grassroots channels of communication. And lets imagine that, partly due to media manipulation by the oligarchs, the majority of the electorate, of all parties, had forgotten everything that they ever learned in Civics class.
In this totally hypothetical situation-- but please bear with me, and imagine, for the sake of this fun intellectual exercise, that someday this could somehow happen in the US, in theory...
What remaining US gov't checks and balances would there be? How could that corruption scenario be thwarted?
(For example, is there a way for a minority in Congress to successfully bring charges? Does the FBI or some other agency have powers to investigate and intervene, below the radar? Does Judicial have any power to intervene, perhaps if petitioned? Do states have rights to contest the situation? What if there is also a treason angle; does that activate powers from anywhere else in the government to intervene?)
If this scenario was discussed in Civics class, it flew right over my head at the time, but now seems interesting.