WATCH: Trump speaks after judges express skepticism of claims that he's immune from prosecution

Donald Trump is set to return for the first time in months to the federal courthouse in Washington as an appeals court hears arguments Tuesday on whether the former president is immune from prosecution on charges that he plotted to overturn the results of the 2020 election.

WASHINGTON (AP) — With Donald Trump present for the first time in months, federal appeals court judges in Washington expressed deep skepticism Tuesday that the former president was immune from prosecution on charges that he plotted to overturn the results of the 2020 election.

The panel of three judges, two of whom were appointed by President Joe Biden, also questioned whether they had jurisdiction to consider the appeal at this point in the case, raising the prospect that Trump's effort could be dismissed.

During lengthy arguments, the judges repeatedly pressed Trump's lawyer to defend claims that Trump was shielded from criminal charges for acts that he says fell within his official duties as president. That argument was rejected last month by a lower-court judge overseeing the case against Trump, and the appeals judges suggested through their questions that they, too, were dubious that the Founding Fathers envisioned absolute immunity for presidents after they leave office.

“I think it’s paradoxical to say that his constitutional duty to take care that the laws be faithfully executed allows him to violate criminal law," said Judge Karen LeCraft Henderson, an appointee of former President George H.W. Bush.

The outcome carries enormous ramifications both for the landmark criminal case against Trump and for the broader, and legally untested, question of whether an ex-president can be prosecuted for acts committed in the White House. It will also likely set the stage for further appeals before the U.S. Supreme Court, which last month declined a request to weigh but could still get involved later.

A swift decision is crucial for special counsel Jack Smith and his team, who are eager to get the case — now paused pending the appeal — to trial before the November election. But Trump's lawyers, in addition to seeking to get the case dismissed, are hoping to benefit from a protracted appeals process that could delay the trial well past its scheduled March 4 start date, including until potentially after the election.

Underscoring the importance to both sides, Trump, the 2024 Republican presidential primary front-runner, intends to attend Tuesday's arguments even though the Iowa caucuses are just one week away and despite the fact that there's no requirement that defendants appear in person for such proceedings.

In his first court appearance in Washington — one of four cities where he faces criminal prosecutions — since his arraignment in August, Trump sat at the defense table, watching intently and occasionally taking notes and speaking with his lawyers.

He’s already signaling that he could use the appearance to portray himself as the victim of a politicized justice system. Though there’s no evidence Biden has had any influence on the case, Trump’s argument could resonate with Republican voters in Iowa as they prepare to launch the presidential nomination process.

On his way to court on Tuesday, he said in a fundraising email that he was going “to fight for my rights as Crooked Joe and his Special Counsel of “war crimes prosecutors” are attempting to strip them from me.”

Former presidents enjoy broad immunity from lawsuits for actions taken as part of their official White House duties. But because no former president before Trump has ever been indicted, courts have never before addressed whether that protection extends to criminal prosecution.

Trump’s lawyers insist that it does, arguing that courts have no authority to scrutinize a president’s official acts and that the prosecution of their client represents a dramatic departure from more than two centuries of American history that would open the door to future “politically motivated” cases. They filed a similar motion on Monday in another criminal case against Trump in Georgia.

“To authorize the prosecution of a president for official acts would open a Pandora’s box from which this nation may never recover,” said D. John Sauer, a lawyer for Trump, asserting that, under the government's theory, presidents could be prosecuted for giving Congress “false information” to enter war or for authorizing drone strikes targeting U.S. citizens abroad.

He later added: “If a president has to look over his shoulder or her shoulder every time he or she has to make a controversial decision and wonder if ‘after I leave office, am I going to jail for this when my political opponents take power?’ that inevitably dampens the ability of the president.”

But the judges were skeptical about those arguments. When Sauer asserted that under the Constitution, Trump could not be prosecuted for conduct for which he had been impeached and acquitted before Congress, Judge Florence Pan suggested that that argument actually undermined his absolute immunity claim because he was conceding situations in which an ex—president could be charged.

“Once you concede that presidents can be prosecuted under some circumstances, your separation of powers argument falls away,” Pan said.

Asides from the merits of the arguments, the judges jumped right into questioning Trump’s lawyer over whether the court has jurisdiction to hear the appeal at this time. Sauer said presidential immunity is clearly a claim that is meant to be reviewed before trial. Smith's team also said that it wants the court to decide the case now.

Smith's team maintains that presidents are not entitled to absolute immunity and that, in any event, the acts Trump is alleged in the indictment to have taken — including scheming to enlist fake electors in battleground states won by Biden and pressing his vice president, Mike Pence, to reject the counting of electoral votes on Jan. 6, 2021 — fall far outside a president's official job duties.

“The president has a unique constitutional role but he is not above the law. Separation of powers principles, constitutional text, history, precedent and immunity doctrines all point to the conclusion that a former president enjoys no immunity from prosecution,” prosecutor James Pearce said, adding that a case in which a former president is alleged to have sought to overturn an election “is not the place to recognize some novel form of immunity.”

When Henderson asked how the court could write its opinion in a way that doesn’t open the “floodgates” of investigations against ex-presidents, Pearce said he did not anticipate “a sea change of vindictive tit-for-tat prosecutions in the future.” He called the allegations against Trump were fundamentally unprecedented.

“Never before has there been allegations that a sitting president has, with private individuals and using the levers of power, sought to fundamentally subvert the democratic republic and the electoral system," he said. "And frankly, if that kind of fact pattern arises again, I think it would be awfully scary if there weren’t some sort of mechanism by which to reach that criminally.”

It's not clear how quickly the panel from the U.S. Circuit Court of Appeals from the D.C. Circuit will rule, though it has signaled that it intends to work fast.

U.S. District Judge Tanya Chutkan rejected the immunity arguments, ruling on Dec. 1 that the office of the presidency does not confer a “‘get-out-of-jail-free pass.’” Trump's lawyers appealed that decision, but Smith's team, determined to keep the case on schedule, sought to leapfrog the appeals court by asking the Supreme Court to fast-track the immunity question. The justices declined to get involved.

The appeal is vital to a broader Trump strategy of trying to postpone the case until after the November election, when a victory could empower him to order the Justice Department to abandon the prosecution or even to seek a pardon for himself. He faces three other criminal cases, in state and federal court, though the Washington case is scheduled for trial first.