For those rightly concerned about the timing of Donald Trump’s federal Jan. 6 trial, Thursday’s oral arguments before the Supreme Court gave plenty of reasons for worry. Moreover, the court’s conservative majority seemed inclined to define presidential immunity from prosecution in a way that could undermine some of the charges in special counsel Jack Smith’s indictment.

Much of the court’s questioning went well beyond the immediate issue of Trump’s immunity for the criminal acts alleged. The court’s conservatives focused almost exclusively on abstract questions of immunity for future presidents rather than the charges against the former president. Even the more moderate members of the conservative majority seemed preoccupied with the difficulty of drawing the line between official and unofficial acts, assuming that the former deserve extensive protection from prosecution.

Justice Amy Coney Barrett read a litany of acts from the indictment and asked Trump’s lawyer whether they were official or not. Chief Justice John G. Roberts Jr. indicated that the line between public and private presidential conduct is hard to draw, saying he was concerned that the D.C. Circuit Court of Appeals “did not get into a focused consideration of what acts we’re talking about or what documents we’re talking about.”

At best, the court’s questioning augurs an opinion setting out general principles of immunity and necessitating a remand to the lower courts to apply the justices’ guidance. As Justice Neil M. Gorsuch put it, “We’re writing a rule for the ages.” That would add further delay to a schedule that already seems to be putting a trial shortly before or beyond the November election.

And that wasn’t even the most serious implication for Smith’s case.

The conservative justices’ questioning of Michael Dreeben, the special counsel’s well-regarded Supreme Court specialist, was sharp and fast. And their questions to both sides suggested they might conclude that inquiring into a president’s motives for certain acts would violate the constitutional separation of powers. That would point to a decision requiring the courts to set aside all evidence of a president’s malign intent.

If motive has to be disregarded in determining whether the president’s actions are official or not, it could undermine much of the case against Trump — including, for example, his brazen attempt to strong-arm the Department of Justice into falsely informing Georgia officials that the state’s election results were flawed.

Such a limitation might even provide immunity in the hypothetical extreme proposed during arguments before the D.C. Circuit: a president ordering Navy Seals to assassinate a political opponent. The force of that example is that it shows how an official act could have a patently malign motive.

As Justice Elena Kagan interjected in reference to the implications of her colleagues’ questions and Trump lawyer John Sauer’s response: “You’re asking us to say that a president is entitled … for total personal gain, to use the trappings of his office.” Exactly right.

Gorsuch threw another lifeline to Trump’s lawyer, asking whether he would accept a definition of official acts like the one in the D.C. Circuit’s opinion in Blassingame vs. Trump, which concerned presidential immunity from civil suits. That case drew a distinction between Trump’s acts as an officeholder and as an office-seeker. Applying it to the criminal case would likely immunize Trump for some of the conduct in the indictment, in particular his allegedly corrupt use of the Justice Department, though he would presumably remain on the hook for political conduct such as organizing false electors.

It got worse for the prosecution. More or less out of nowhere, Justice Brett M. Kavanaugh suggested that one of the charges against Trump, conspiracy to defraud the United States, relies on a statute that is so broad and vague that it could be misused by future prosecutors against future presidents. Justice Samuel A. Alito Jr. jumped in to second the suggestion, taking up a criticism of the prosecution that Trump’s lawyers hadn’t even raised.

Since the court just heard arguments in a separate case that could invalidate two of the four charges against Trump — those under a federal obstruction statute — an opinion invalidating another charge could force Smith to soldier on with only one remaining charge against Trump, conspiracy against rights. That charge relies on the electorate’s right to have votes counted, which is a somewhat indirect approach to accountability for Trump’s pernicious post-election conduct.

That’s not all. Kavanaugh also raised the Trump team’s suggestion that perhaps Congress should have to make a “clear statement” of intent to apply any criminal law to the president, a stratagem the court previously conjured to deal with separation-of-powers concerns. Justice Sonia Sotomayor pointed out that it would in effect excuse a president for violations of most of the federal code.

Dreeben hardly had time to make his points until the end of the nearly three-hour argument, when Kagan gave him some room to do so. Kagan also asked the special counsel’s representative a friendly question getting at the possibility that the court could limit its decision to the charges against Trump to permit the trial to go forward expeditiously. But the odds that the court will take that guidance now look extremely slim.

Going into Thursday’s showdown, the critical question was whether the court’s opinion would permit the trial to go forward without further proceedings. In the wake of the arguments, that seems more unlikely than ever. Indeed, the court’s questions raised the additional alarming prospect that it could confer the kind of expansive presidential immunity that would further weaken the constitutional principle that a president is not a king.

Harry Litman is the host of the “Talking Feds” podcast and the Talking San Diego speaker series. @harrylitman