Why an Immunity Ruling in Trump’s Favor Might Not Alter the Shape of His Trial

If the Supreme Court rules that Donald J. Trump is immune from being charged with crimes over official actions he took as president, it would be a momentous decision for the future of executive power and American-style democracy.

But it is far from certain that such a ruling would derail the election subversion case against him. In fact, there is a scenario in which the court could render such a ruling without altering the charges or the array of evidence that the special counsel, Jack Smith, wants to present to a jury.

Mr. Trump faces four criminal counts over his efforts to overturn his loss of the 2020 election, but none are exclusively centered on conduct Mr. Trump undertook in his capacity as president. Rather, the indictment tells a story that mixes both official acts with private ones, meaning actions Mr. Trump took in his role as a candidate for office. It then declares that each charge arises from the entire picture.

Among the accusations: Mr. Trump spread false claims of voter fraud, plotted to recruit false slates of electors from swing states, pressured Vice President Mike Pence to use their existence to block Congress’s certification of Joseph R. Biden Jr.’s Electoral College victory, and urged lawmakers to use the attack on the Capitol by his supporters to delay any vote.

As of yet, no court has decided which of Mr. Trump’s actions are considered official presidential conduct, versus private, unofficial campaign activity. But during oral arguments before the Supreme Court on Thursday, Justice Amy Coney Barrett floated the possibility that Mr. Smith could “just proceed based on the private conduct and drop the official conduct.”