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Donald Trump has asked the federal judge overseeing special counsel Jack Smith’s election interference case to dismiss the criminal charges, arguing he has immunity because he was president at the time and also was acquitted by the US Senate after his impeachment.

Thursday’s filing may set up a fight that eventually goes to the Supreme Court. While courts have held presidents can be immune from civil liability for their actions while in office, novel legal questions about whether that extends to criminal prosecutions remains unsettled.

The indictment, handed up by a Washington, DC, grand jury in August, alleges that Trump illegally plotted to stay in office after losing the 2020 election.

Prosecutors allege that Trump, along with several of his lawyers and advisers, tried to implement a plot to appoint a fake slate of electors and spread misinformation about voting security, all of which ultimately led to the violence at the US Capitol on January 6, 2021.

In their filing with US District Judge Tanya Chutkan, Trump’s attorneys argued that the charges should be dismissed because Trump, in working to “ensure election integrity,” was operating in his official capacity as president and therefore is protected under presidential immunity.

“Breaking 234 years of precedent, the incumbent administration has charged President Trump for acts … at the heart of his official responsibilities as President,” the filing states.

“The prosecution falsely claims that President Trump’s motives were impure – that he purportedly ‘knew’ that the widespread reports of fraud and election irregularities were untrue but sought to address them anyway,” his attorneys wrote.

“But as the Constitution, the Supreme Court, and hundreds of years of history and tradition all make clear, the President’s motivations are not for the prosecution or this Court to decide. Rather, where, as here, the President’s actions are within the ambit of his office, he is absolutely immune from prosecution.”

Trump’s lawyers also point to the Senate acquitting the former president in February 2021 on charges that he incited an insurrection on January 6, 2021.

“President Trump was acquitted of these charges after trial in the Senate, and he thus remains immune from prosecution. The Special Counsel cannot second-guess the judgment of the duly elected United States Senate,” Trump’s lawyers wrote.

They also wrote: “Importantly, this recognition of absolute immunity, regardless of internal motivation, does not place the President ‘above the law,”’ but instead simply clarifies that the remedy for alleged official misconduct lies, as the Constitution requires, with Congress through impeachment, and through other informal means.”

The ‘outer perimeter’ of the presidency

Some of the legal arguments made by Trump in the filing have also been raised by his attorneys in a separate civil case brought against him by Democratic members of the House and Capitol Police officers who are seeking to hold him accountable for the January 6 attack.

In that case, which is currently before the appeals court based in Washington, DC, Trump is arguing that his conduct related to the attack also is shielded by presidential immunity because it falls within the “outer perimeter” of presidential duties.

A 1982 ruling from the US Supreme Court established that presidents are absolutely immune from civil damages arising from their official acts as president – but when presidential speech amounts to an official act is still a murky question for the courts.

In their filing Thursday, Trump’s attorneys repeatedly invoked the decision in that case, Nixon v. Fitzgerald, arguing the conduct at the heart of Smith’s indictment is protected by the precedent.

“To ensure the President may serve unhesitatingly, without fear that his political opponents may one day prosecute him for decisions they dislike, the law provides absolute immunity for acts within the ‘outer perimeter’ of [the President’s] official responsibility,’” they wrote.

They also noted: “No court has addressed whether such Presidential immunity includes immunity from criminal prosecution for the President’s official act.”

Smith’s team is likely to push back aggressively against the arguments made in Thursday’s filing.

Earlier this year, Justice Department attorneys urged the appeals court in the civil case against Trump to reject the arguments his attorneys made in that matter, saying in a friend-of-a-court brief that a president can’t be absolutely immune for speech on a matter of public concern if the speech is found to have incited violence.

“No part of a president’s official responsibilities includes the incitement of imminent private violence,” the attorneys told the court.

This story has been updated with additional details.