The first case cited as precedent in the first Supreme Court brief filed by lawyers for President Trump since he took office this year was Trump v. United States, the July decision that gave him substantial immunity from prosecution. That citation was the first of nine. A second brief, filed days later, cited the decision eight more times.
It was at first blush a poor fit. The issue in the new case, the first arising from a challenge to the administration’s blitz of executive actions, was whether Mr. Trump could fire the leader of an independent agency without cause. It had nothing to do with prosecutions or immunity, presidential or otherwise.
But Mr. Trump’s lawyers had good reason to rely on the decision. Its legacy, scholars say, will not be its three-part test for determining whether prosecutions of former presidents can proceed. It will be how the decision amplified presidential power just in time for a new administration determined to test its limits.
The decision, ostensibly about the important but limited question of immunity, contained “some of the most far-reaching pronouncements about presidential power in the court’s history,” Jack L. Goldsmith, a law professor at Harvard and a former Justice Department official in the administration of President George W. Bush, wrote in “The Presidency After Trump v. United States,” a draft article posted last week that is to be published in The Supreme Court Review.
The opinion, he added, “amounted to perhaps the most consequential disquisition ever on the law of the presidency.”
Chief Justice John G. Roberts Jr., writing for the majority, made the case for a vigorous and energetic president whose core responsibilities cannot be constrained by Congress and the courts. “Unlike anyone else,” he wrote, “the president is a branch of government, and the Constitution vests in him sweeping powers and duties.”
The recent briefs were filed in a case about whether Mr. Trump could fire Hampton Dellinger, who led a government watchdog agency, without complying with a statute that required the president to give a good reason.
Mr. Dellinger’s case is over. The Supreme Court dismissed it as moot on Thursday after he gave up his fight. The court had issued only an interim ruling in the meantime, one that did not grapple with implications of the immunity decision.
But the outsize role that the decision played in the government’s briefs in the Dellinger case will doubtless recur in new cases that challenge Mr. Trump’s executive orders claiming the power to fire all sorts of federal workers, restructure the government and freeze funds appropriated by Congress.
As scholars digest and consider the immunity decision, some of them have started to conclude that its most important elements were largely overlooked when it landed last summer, as the presidential campaign was nearing its final stages.
Most people focused on the ruling’s practical impact, which was to delay beyond Election Day Mr. Trump’s trial on charges that he tried to overturn the 2020 election. That meant the public could not consider the evidence gathered by Jack Smith, the special counsel overseeing the prosecution, in time to take account of it at the polls. (Mr. Smith dropped the case after Mr. Trump reclaimed the presidency.)
Others focused on the three-part test announced in the majority opinion for deciding whether former presidents accused of committing crimes while in office may be prosecuted: absolute immunity for core duties, at least presumptive immunity for all other official conduct and no immunity for private acts.
That discussion was mostly cryptic and unsatisfying. If there was clarity, it was in the chief justice’s discussion of the first category — absolute immunity. He wrote that the president had some exclusive responsibilities that could not be overridden by Congress.
One was the freedom to fire many appointees for any reason at all. The other was to control the Justice Department’s investigations and prosecutions.
Professor Goldsmith wrote that “these were the most far-reaching rulings in the decision.”
Christine Kexel Chabot, a law professor at Marquette University, questioned the ruling’s commitment to originalism, the mode of constitutional interpretation often favored by conservatives that seeks to determine the document’s original public meaning.
“The court’s approach creates a far more powerful presidency than was ever recognized by the founding generation,” she wrote in an article to be published in The University of Michigan Journal of Law Reform.
In all, Professor Goldsmith concluded, “the court has traditionally proceeded cautiously and carefully when marking out exclusive presidential power because the president is known to run hard with such power.”
“But it did the opposite in Trump,” he wrote, referring to the decision. “It issued an incautious and uncareful ruling on broadly applicable exclusive presidential powers that presidents will use to their enormous new advantage vis-à-vis the other two branches, especially Congress, until the court, in more considered reflection, decides that it ruled imprudently and went too far.”
