what if one day a presidential candidate that was bought and paid for by lobbyists got into the white house and then broke all the promises they made to their donors?
if a hypothetical closeted Marxist who tricked their corporate backers got into the white house what could they do with that power?
If they're alone, then it wouldn't be much.
Like, they'd have to have spent their entire political career doing two things successfully: 1) playing the game well enough to fool any groups that would instantly mobilize to neutralize any actual leftist politician gaining real power and 2) incubating or head hunting an army of leftists who'd be willing to risk their lives and their families' lives who would have had to been doing the same thing as this President - being leftists but keeping their power level hidden.
If successful, this army would need to be immediately installed in every available position that the President has the unilateral authority to appoint. A complete purge of all previous personnel no matter how inconsequential the position seems, down to cooks and grounds keepers and unpaid interns.
The political persona would need to be as bombastic as Trump. During the long road to the Presidency they'd have to have been taking extensive notes and collecting blackmail material on EVERYBODY. The flip from establishment to anti-establishment could be justified by showing the receipts. "Hey everybody, to get to the Presidency, here's all the disgusting shit I witnesses at fundraisers and closed door meetings. Here are some names, here are some pictures, here are some recordings. You all, the American people, can do with that what you will."
If the court system is still packed with chuds and liberals, then just ignore their verdicts. Like, the supreme court of the USA has no enforcement capacity. Any ruling can be ignored by anybody and if the President isn't going to send in the federal agencies to enforce a SCrOTUS decision its going to be hard for their decision's to matter.
Line item vetos and executive orders should have been planned for and prewritten well before taking the presidency. This Pres only has two jobs for the first 6~12 months, bully pulpit speeches inciting the public to pretty much go to war against the capitalists and their fascist enforcers and practically non-stop executive orders. The VP should pretty much be stomping through congress daily with "You will eat the bugs, you will sleep in the pod" energy.
Always remain armed and train as often as possible at close quarter fighting.