But which of those actually fits the present situation? Four years haven't passed. Congress is not dissolved. It's literally just a bunch of executive orders and firings within the executive branch, which, last time I checked Article II, is under the authority of the president.
I think “unlawfully assume extraordinary powers” may apply.
It’s certainly debatable, but shutting down agencies created and authorized by Congress and refusing to distribute funding legislated by Congress seems to be an overstep of executive power, and therefore an undermining of Congress’s power.
My main point was that ousting an incumbent or defying an election is not a requirement for something to be a coup, as the previous comment was suggesting. A legitimately elected official seizing more power than they are legally entitled to is a form of coup.
anyone can call anything anything, sure(is it a "coup" when I paint a good painting, or win a game of chess? https://www.thefreedictionary.com/coup), but the great-grandparent comment referred to a "bizarre and highly illegal" coup.