Washington — The Supreme Court is set to consider Thursday whether former President Donald Trump is entitled to sweeping immunity from federal prosecution for conduct that occurred while he was in the White House, thrusting the justices into election-year politics in a historic case with significant ramifications for his legal and political future.

Known as Trump v. U.S., the dispute is the second this term in which the nation's highest court will step into a legal battle that presents a question it has never confronted before, and one with consequences for the former president and the November election. 

Its decision will be crucial for determining whether special counsel Jack Smith's case against Trump can head to trial. A ruling in Trump's favor would bring the prosecution to an end. But if Smith prevails — as he has done twice in lower courts — and Trump's claims of immunity are rejected, the case would pick back up after being paused for months. It is still unclear how quickly it could go to trial.

The stakes of the Supreme Court case

A victory for the special counsel would also significantly raise the stakes of the 2024 election for Trump, since he could order the Justice Department to drop the case if he retakes the White House.

"Here we are, 236 years from the Constitution. It should tell us something that it has taken us this many years for someone to make this bold claim," said Jonathan Entin, a professor emeritus of law at Case Western Reserve University. "I understand that this is the first time that a former president has been charged with a serious crime, so maybe that explains why this hasn't come up before, but this is also the first time in our history that a president who has been defeated for reelection has basically refused to recognize the fact that he has lost."

In this court fight, the justices are tasked with deciding whether the doctrine of presidential immunity extends to criminal prosecution for acts undertaken by a former president while in office. The Supreme Court has a 6-3 conservative majority, and Trump appointed three of its members.

Arguments in the case will be the last heard by the justices in its current term, which has featured a series of legal battles that have directly or indirectly involved Trump. The Supreme Court in March said states cannot bar Trump from the 2024 ballot using a rarely invoked provision of the 14th Amendment, overturning a blockbuster decision from Colorado's highest court that deemed him ineligible for the presidency. 

The proceedings are also occurring alongside the historic criminal trial involving Trump taking place in Manhattan, where he is charged with 34 state felony counts for falsifying business records. The former president pleaded not guilty to those charges, and unsuccessfully attempted to have them tossed out on immunity grounds. A request for him to be excused to attend Supreme Court oral arguments in Washington was denied by the judge overseeing his New York trial.

The Trump immunity case

Thursday's arguments stem from four criminal counts a federal grand jury brought against Trump in connection to his alleged efforts after the 2020 election to thwart the certification of Joe Biden's victory. The former president pleaded not guilty to all counts last year and the case is currently on hold as the Supreme Court considers Trump's claims of absolute immunity.

Two lower courts — including a unanimous three-judge appeals court panel in the nation's capital — rejected Trump's claim that previously serving as president shields him from charges tied to conduct that happened while he was still the chief executive. His attorneys are asking the justices to reverse those rulings, arguing in briefs that Trump's actions after the election were "official" in nature and therefore immunized from being considered criminal. 

The question before the justices — who rejected Smith's request to let the appeals court decision stand on its own —  is "whether and if so to what extent does a former president enjoy presidential immunity from criminal prosecution for conduct alleged to involve official acts during his tenure in office."

In 1982, the Supreme Court ruled that a president is immune from civil liability for acts taken within the "outer perimeter" of his official duties. But it has never before considered whether that sweeping immunity extends to criminal prosecution.

Trump is the first former president in the nation's history to face criminal charges, and his prosecution in Washington is one of four cases being pursued — two in federal courts and two in state courts. He has pleaded not guilty to all charges and claimed the prosecutions are politically motivated.

His legal team has said that the unprecedented nature of his prosecution is evidence that presidents are protected from criminal charges. 

"From 1789 to 2023, no former, or current, president faced criminal charges for his official acts — for good reason," Trump's lawyers told the court in a filing last month. "The president cannot function, and the presidency itself cannot retain its vital independence, if the president faces criminal prosecution for official acts once he leaves office."

Trump's attorney, D. John Sauer, is set to argue before the court. He will likely echo his earlier claims that the former president's actions between the 2020 presidential election and the Jan. 6, 2021, Capitol attack described in the special counsel's indictment were pursued under his authority as president, not in his capacity as a candidate for office.

"Once our nation crosses this Rubicon, every future president will face de facto blackmail and extortion while in office, and will be harassed by politically motivated prosecution after leaving office, over his most sensitive and controversial decisions," Sauer told the Supreme Court in the filing. "That bleak scenario would result in a weak and hollow President, and would thus be ruinous for the American political system as a whole."

The former president's lawyers have also claimed that presidents can only be prosecuted if they were first impeached by the House and convicted by the Senate. Trump was impeached by the House on a single article of incitement of insurrection after the Jan. 6, 2021, attack on the U.S. Capitol but acquitted by the Senate.

But the special counsel has successfully urged lower courts to endorse the opposing view: that the Constitution does not vest a president with absolute immunity from criminal prosecution, especially when tied to the private act of campaigning. 

In a brief filed to the Supreme Court earlier this month, prosecutors argued, "No presidential power at issue in this case entitles the president to claim immunity from the general federal criminal prohibitions supporting the charges: fraud against the United States, obstruction of official proceedings, and denial of the right to vote."

Smith has alleged that Trump engaged in a multi-pronged scheme to subvert the transfer of presidential power, and his actions were all taken to achieve a private goal: to stay in office for a second term.

Michael Dreeben, a member of Smith's team who previously served as deputy solicitor general, will argue in court on Thursday. The special counsel has asserted in court filings that Trump's alleged conduct "frustrates core constitutional provisions that protect democracy."

The special counsel told the justices that there are "layered safeguards" when a criminal case is brought that "provide assurance that prosecutions will be screened under rigorous standards and that no president need be chilled in fulfilling his responsibilities by the understanding that he is subject to prosecution if he commits federal crimes."

Smith's team directly took on Trump's lawyers' claim that the charges against the former president lack historic legal precedent, writing: "The absence of any prosecutions of former presidents until this case does not reflect the understanding that presidents are immune from criminal liability; it instead underscores the unprecedented nature of petitioner's alleged conduct." 

Even if the justices decide that former presidents can't be criminally charged for official acts, prosecutors wrote that Trump's alleged conduct outlined in the indictment was a "private scheme with private actors to achieve a private end: petitioner's effort to remain in power by fraud."

The special counsel told the court that an alleged plan to overturn the outcome of the presidential election is the "paradigmatic example of conduct that should not be immunized, even if other conduct should be."

A return to the Supreme Court

Even if the Supreme Court ultimately rejects Trump's arguments and paves the way for his prosecution, its decision to consider the case in the first place added months of delay to the proceedings. 

U.S. District Court Judge Tanya Chutkan, who was assigned to oversee the case, previously set the trial for March, but tossed out that schedule while the D.C. Circuit considered the immunity appeal.

Chutkan ruled in December that Trump's claims of immunity were invalid, writing, "the United States has only one chief executive at a time, and that position does not confer a lifelong 'get-out-of-jail-free' pass" from prosecution. 

The former president appealed that decision. In an attempt to accelerate the proceedings, Smith's team asked the Supreme Court to bypass the D.C. Circuit and take the unusual step of considering the immunity question before the appeals court ruled.

The justices rejected that request and opted to allow the D.C. Circuit to hear and decide the case first.

Once a three-judge panel ruled unanimously against Trump earlier this year, Smith asked the court to let that decision stand and decline to further consider the matter. Although the Supreme Court decided to intervene, it is moving quicker than it typically does, and the justices are likely to rule by the end of June.

Entin, from Case Western Reserve University, said that though the Supreme Court has not acted as quickly as Smith wanted, it is still under time pressure, and drawing the line between what is and isn't an official act that may be covered by presidential immunity is a difficult task.

"From an institutional standpoint, there are powerful reasons for the court to rule less broadly than President Trump is asking for," he said.

Trump's reasoning for sweeping immunity is difficult to reconcile with the law and historical record, Entin said.

"Accepting Trump's argument in this case basically means that presidents are above the law," he said. "They are not really accountable for their actions, and it is hard for me to believe that the Supreme Court will say that."

Robert Legare

Robert Legare is a CBS News multiplatform reporter and producer covering the Justice Department, federal courts and investigations. He was previously an associate producer for the "CBS Evening News with Norah O'Donnell."