The Supreme Court is set to decide this month on whether presidents are entitled to “absolute immunity” for official acts, a ruling that could make or break the prosecution of President Trump. 

The Nine heard oral arguments in April on the immunity issue in a case that arrived at the high court from the District of Columbia district court of Judge Tanya Chutkan. She ruled that Trump is not entitled to immunity for the acts that underpin Special Counsel Jack Smith’s and District Attorney Fani Willis’s indictments. Judge Chutkan wrote that Trump is not entitled to the “divine right of kings.”

A panel of three riders from the United States Circuit Court for the District of Columbia agreed with Judge Chutkan that Trump is not entitled to the protections of the presidency with respect to Mr. Smith’s charges. In Nixon v. Fitzgerald, the Supreme Court had ruled that immunity in civil cases extends to the “outer perimeter” of official acts. Trump’s attorney, John Sauer, conceded that private acts are not entitled to immunity. 

The justices appeared sympathetic to Mr. Sauer’s case. Justice Neil Gorsuch reflected that he was “not concerned about this case” but that he is “concerned about future uses of the criminal law to target political opponents based on accusations about their motives.” He added that the high court is tasked with “writing a rule for the ages.”

By Justice Gorsuch’s logic, it is not so clear why presidents should not be immune for criminal cases involving not only official acts, but unofficial ones too. After all, Justice Gorsuch is worried about the harassment of former presidents for political reasons — as is allegedly occuring in New York County now. Chief Justice Roberts summarized the D.C. Circuit’s rule as a “former president can be prosecuted because he’s being prosecuted.”

The attorney for the Department of Justice, Michael Dreeben, sought to reassure the justices that a narrow reading of immunity would not unleash the de rigeur prosecution of former presidents. He called courts and the criminal justice system the “ultimate check” on presidential power and pointed to due process rights and the operation of, say, grand juries,  as features of the “carefully balanced framework” that could stem a flood of prosecutions. 

Justice Samuel Alito wondered if a limited holding on immunity would incentivize presidents to “pardon themselves from anything that they might have been conceivably charged with committing” and that tit for tat prosecution could “lead us into a cycle that destabilizes the functioning of our country as a democracy.” Mr. Dreeben responded that political considerations could serve as a check against liberal use of the pardon power. 

Mr. Dreeben’s argument, though, flies in the face of one of the clearest indication of what the Framers intended by granting the pardon power solely to the president. They wanted it to be used robustly. Alexander Hamilton writes in 74 Federalist that its exercise is to be as “little as possible fettered or embarrassed.”

In any event, any Supreme Court ruling that takes Trump’s position on immunity — even partially — could be disastrous for Mr. Smith’s prosecution. The justices could remand the case back to Judge Chutkan to adjudicate which acts in the indictment are public and which are private, a process that could take months. Mr. Dreeben in court appeared committed to Justice Amy Coney Barrett’s suggestion that Mr. Smith pare down his indictment to what even Trump’s team agrees are purely private acts. 

A ruling in Trump’s favor could also affect Ms. Willis’s state prosecution of the 45th president for attempting to overturn the results of the 202 election, though Mr. Smith would likely attempt to contain the fallout by arguing that such immunity would only hold in federal court, not a state one. 

Trump attempted to claim immunity in his hush money case at Manhattan, but Judge Juan Merchan ruled that argument was not raised in a timely fashion. A federal judge, Alvin Hellerstein, had previously ruled that “money paid to an adult-film star is not related to a President’s official acts,” a determination that Trump and his lawyers did not appeal. Judge Chutkan could soon be tasked with making that determination with respect to January 6.