For one thing, the Supreme Court are the ones that ruled that the president has some form of immunity in the first place, and it wouldn't be that unprecedented for them to rein that in a bit if it comes to them again; see the follow-up to Bruen in Rahimi where basically all of them other than Thomas seemed to want to walk back their previous ruling a bit. Although it's hard for me to imagine how they could have been surprised at all about the aftermath of their ruling in Bruen, it does sometimes seem to me like some of the more "moderate" conservative justices forget that they're playing with live ammo (if you'll pardon the pun) and not just debating abstract principles. I don't pretend to have any sort of confidence in what they'd actually do if presented with another case against Trump, but I don't think it would be _that_ surprising if they decided to try to find some technicality where they can claim he still has immunity for most things but for some reason it wouldn't apply to the current issue under question. I'm also not going to claim with any sort of confidence that ruling against him would be effective at reining him in, since there already seems to be a large contingent of his supporters eager for him to just flat out ignore court rulings that have much less personal stakes for him.

The other remedy that still technically merits a mention even if it's somewhat implausible to happen any time soon is that Congress does still have the power to impeach and remove the president. I don't see it as super likely that Republicans would turn against him at this point, since pretty much all of the internal opposition has been driven out of the party over the past decade, but I'm guessing that it also would have been almost unthinkable for Nixon to go from winning every state other than Massachusetts in 1972 to losing so much support in 1974 that his own party told him that he might as well resign rather than have more than half of his own party's senators vote with the Democrats to remove him from office[0]. Even though I think the people who voted for Trump tend to be much more passionate in their support for him, and the norms for what behavior is considered "acceptable" as a politician have expanded dramatically (not in small part from Trump himself), I think there's still an argument to be made that Trump isn't as popular as Nixon was at this point in second term, and it's at least theoretically possible to imagine a scenario where his support eroded to the point that he lost enough support to continue with what he's doing. Even if his supporters aren't ever going to turn against him, there aren't nearly as many of them that there were for Nixon, so maybe the most likely of the unlikely scenarios for this would be a large enough Democrat majority getting elected during the midterms that they (possibly along with some of the few remaining moderate Republicans in the Senate) could remove him. (This would of course still leave Vance as president, assuming he didn't also get impeached and convicted, so he could pardon Trump, but that still removes him from power for at least couple of years, and Vance being a relatively recent convert to Trumpism doesn't seem like he'd be able to command nearly as much loyalty as Trump himself has).

As for what could actually cause something like this to take place, I have to wonder if the most likely scenario would literally be another pandemic. Not only does the previous one have a reasonable claim to being what caused him to lose in 2020, a lot of the policies he's currently enacting seem like they'd backfire spectacularly in the face of another pandemic (e.g. cutting vaccine mandates in schools, appointing Kennedy as HHS secretary when him being antivax is probably the most well known thing about him, and the recent flirting with cutting Medicaid in order to pay for the tax cuts...)

[0]: from https://en.wikipedia.org/wiki/Impeachment_process_against_Ri...:

> During the late afternoon of August 7, Senators Goldwater and Scott and Congressman Rhodes met with Nixon in the Oval Office and told him his support in Congress had all but disappeared. Scott told reporters afterward that they did not pressure Nixon to resign, but simply told the president that "the situation is very gloomy on Capitol Hill." Rhodes told the president he would face certain impeachment when the articles came up for vote in the full House. By Majority Leader O'Neill's estimate, no more than 75 representatives were willing to vote against the obstruction-of-justice article. Goldwater and Scott told the president that not only were there enough votes in the Senate to convict him, but that no more than 15 or so senators were willing to vote for acquittal. Goldwater later wrote that as a result of the meeting, Nixon "knew beyond any doubt that one way or another his presidency was finished." That night, Nixon finalized his decision to leave office.