The US Supreme Court has found that Donald Trump cannot be prosecuted for actions that were within his constitutional powers as US president in a landmark ruling recognising for the first time any form of presidential immunity from prosecution.
The justices, in a 6-3 ruling authored by Chief Justice John Roberts, threw out a lower court's decision that had rejected Trump's claim of immunity from federal criminal charges involving his efforts to undo his 2020 election loss to Joe Biden.
The ruling marked the first time since America's 18th century founding that the Supreme Court has declared that former presidents may be shielded from criminal charges in any instance.
Ex-president Donald Trump is accused of plotting an insurrection at the Capitol. (AP PHOTO)
"We conclude that under our constitutional structure of separated powers, the nature of presidential power requires that a former president have some immunity from criminal prosecution for official acts during his tenure in office," Roberts wrote.
Immunity for former US presidents is "absolute" with respect to their "core constitutional powers," Roberts wrote, and a former president has "at least a presumptive immunity" for "acts within the outer perimeter of his official responsibility," meaning prosecutors face a high legal bar to overcome that presumption.
In recognising broad immunity for Trump, Roberts cited the need for a president to "execute the duties of his office fearlessly and fairly" without the threat of prosecution.
"As for a president's unofficial acts," Roberts added, "there is no immunity."
Trump hailed the ruling in a social media post, writing: "BIG WIN FOR OUR CONSTITUTION AND DEMOCRACY. PROUD TO BE AN AMERICAN!"
Trump is the Republican candidate challenging Biden, a Democrat, in the US election in a 2020 rematch. The Supreme Court's slow handling of the case and its decision to return key questions about the scope of Trump's immunity to the trial judge to resolve make it improbable he will be tried before the November 5 election on the charges brought by Special Counsel Jack Smith.
Trump's trial had been scheduled to start on March 4 before the delays over the immunity issue. Now, no trial date is set. Trump made his immunity claim to the trial judge in October, meaning the issue has been litigated for about nine months.
In a separate case brought in New York state court, Trump was found guilty by a jury in Manhattan on May 30 on 34 counts of falsifying documents to cover up hush money paid to a porn star to avoid a sex scandal before the 2016 election. Trump also faces criminal charges in two other cases. He has pleaded not guilty in those and called all the cases against him politically motivated.
Justice Sonia Sotomayor wrote "the president is now a king above the law" after the ruling. (AP PHOTO)
Justice Sonia Sotomayor, joined by fellow liberal Justices Elena Kagan and Ketanji Brown Jackson, delivered a sharply worded dissent, saying the ruling effectively creates a "law-free zone around the president."
"When he uses his official powers in any way, under the majority's reasoning, he now will be insulated from criminal prosecution. Orders the Navy's Seal Team 6 to assassinate a political rival? Immune. Organises a military coup to hold onto power? Immune. Takes a bribe in exchange for a pardon? Immune. Immune, immune, immune," Sotomayor wrote.
"In every use of official power, the president is now a king above the law."
Quentin Fulks, Biden's deputy campaign manager, told reporters that the ruling made it easier for Trump "to pursue a path to dictatorship."
"There's no dispute over who Donald Trump is. He is a convicted felon who encourages violence, who wants to throw out the Constitution, who wants to be a dictator, and wants to use his office for revenge and retribution," Fulks added.
Trump also faces election subversion charges in state court in Georgia and federal charges in Florida brought by Smith relating to keeping classified documents after leaving office.
If Trump regains the presidency, he could try to force an end to the prosecution or potentially pardon himself for any federal crimes.