The court will hear arguments on April 25 over whether former presidents can be prosecuted for things they did while in office.
Former President Donald J. Trump urged the Supreme Court on Tuesday to rule that he is absolutely immune from criminal charges stemming from his attempts to subvert the 2020 election.
“The president cannot function, and the presidency itself cannot retain its vital independence,” the brief said, “if the president faces criminal prosecution for official acts once he leaves office.”
The brief, Mr. Trump’s main submission to the justices before the case is argued on April 25, continued to press an expansive understanding of presidential immunity, one that it said was required by the very structure of the Constitution.
“The question of a former president’s criminal immunity presents grave constitutional questions that strike at the heart of the separation of power,” the brief said.
Legal experts said Mr. Trump was unlikely to prevail but added that how and when the court rejects his arguments will effectively determine whether and when Mr. Trump’s trial, which had been scheduled to start March 4, will proceed.
When the Supreme Court agreed to hear the case last month, it set what it called an expedited schedule. But it was not particularly fast, culminating in oral arguments some seven weeks later, on April 25. That delay represented a significant partial victory for Mr. Trump.
