Trump Should Lose. But the Supreme Court Should Still Clarify Immunity.

The Supreme Court has never squarely resolved whether a president’s in-term conduct is immune from criminal prosecution because, before Donald Trump, there were no indicted ex-presidents.

But there are four such indictments now, including Special Counsel Jack Smith’s prosecution in Washington, D.C. — a case built around Mr. Trump’s fraudulent attempt to subvert the 2020 election and extend his presidential term. On Wednesday, the Supreme Court decided to review a decision from a panel of the U.S. Court of Appeals for the District of Columbia Circuit, which rejected Mr. Trump’s claim of presidential immunity in an opinion that was thorough and unanimous.

The Supreme Court’s decision to hear the case means that Mr. Trump’s trial remains in limbo — and the timing of proceedings will likely impact the 2024 presidential election.

All short-term politics aside, the Supreme Court confronts an extraordinary question of American governance: Are ex-presidents immune from prosecution for in-term conduct? And, if so, how much immunity do they have?

Mr. Trump lost badly in the D.C. Circuit, and the margin of that defeat reflects the underlying weakness of his immunity arguments. That very weakness that might tempt the Supreme Court to say too little about the existence and scope of presidential immunity.

That temptation is unfortunate because American democracy is entering a perilous period of extreme polarization — one in which less malfeasant presidents may face frivolous, politicized prosecutions when they leave office.