The Supreme Court is hearing Trump's claim he's immune from criminal prosecution

A genuinely historic event takes place at the Supreme Court on Thursday. The justices hear arguments on Donald Trump's claim that he is immune from prosecution after leaving office for any of his official acts while he was president. Specifically, Trump claims that the steps he took to block the certification of Joe Biden's election were part of his official duties and that he thus cannot be criminally prosecuted.

The question of presidential immunity from criminal prosecution after leaving office has never been decided by the Supreme Court.

NPR special live coverage begins just ahead of the 10 a.m. Supreme Court hearing. Click on the player below to listen or tune in on the NPR app.

President Richard Nixon, while in office, was named an unindicted co-conspirator in the Watergate scandal, but he was not prosecuted then because the Justice Department concluded that under the Constitution, a sitting president could not be criminally prosecuted. Once Nixon resigned in 1974, however, and was no longer protected as a sitting president, he accepted a pardon from President Gerald Ford rather than face criminal charges.

Trump is making a far broader argument for immunity. He contends that he cannot be prosecuted — ever — for his "official acts" as president unless he is first impeached, convicted by the Senate and removed from office. He was impeached twice, but the Senate failed to muster the two-thirds vote needed to convict. So, were the Supreme Court to embrace Trump's argument, it would mean, given modern political realities, that he and future presidents would likely be immune from prosecution after leaving office.

Trump's definition of a protected official act is a broad one, as illustrated by an exchange between his