The justices heard arguments in the immunity case at a special session, the day after what had been the last scheduled argument of its term. Arguments heard in late April almost always yield decisions near the end of the court’s term, in late June or early July.
But a ruling in early summer, even if it categorically rejected Mr. Trump’s position, would make it hard to complete his trial before the election. Should Mr. Trump win at the polls, there is every reason to think he would scuttle the prosecution.
In cases that directly affected elections — in which the mechanisms of voting were at issue — the court has sometimes acted with unusual speed.
In 2000, in Bush v. Gore, the court issued its decision handing the presidency to George W. Bush the day after the justices heard arguments.