He's done it before.
Hey, I know it's kind of fun and not-just-a-little comforting to say, "The country's fucked; we're all fucked." We're all sharing some good ol' fashioned gallows humor. But in truth, it is inconceivable to me (how many times have I said that since 2016) that SCOTUS will go against Marbury v. Madison. I mean that is THE case. Without it, the court, all courts, are totally emasculated. Would the illegitimate Trump-appointed shitbirds and the unrepentant right wing nuts (Alito and Thomas) side with Trump on certain things? Probably. But on this? To cut their own power, let alone abandon the rule of law that has existed for over 200 years? I don't think so.
At the state and federal district level, the courts can order the local law enforcement (sheriffs, constables and U.S. marshals) to do shit - levy property, execute bench warrants, etc. I don't know for sure, but there has to be something similar at the Supreme Court level, where SCOTUS sends an order to the U.S. marshals to enforce their orders. If the marshals break faith and their oaths and refuse then that could be the breaking point. Or, if the marshals show up to DOGE headquarters, or whatever, and they are met with armed resistance, either by other federal law enforcement officials or otherwise, that could be another breaking point.
My opinion - I don't think the bastards have the balls to go through with it all the way to the violence phase. Right now it's all rhetoric and I think that's what it will remain. I continue to maintain that this is the cartoon version of a fascist dictatorship. Yes, the president does have certain real powers that we can't do anything about - pardoning Jan. 6th traitors, deporting our cheap labor workforce, etc. But the shit he cannot do, which is being challenged in court, will probably come out the right way, i.e. unconstitutional. Trump and his band of wannabe fascists will bitch and demonize. Some judges might get assassinated because of it, actually, by some true-believer dipshit. But that's as far as I predict it will go.