The Supreme Court’s ruling that presidents possess immunity for official acts not only upends the charges handed up by Special Counsel Jack Smith in his January 6 case: It could also cut off his access to the evidence he needs to mount a trial. 

Mr. Smith now must worry about a so-called mini-trial — a series of hearings where Judge Tanya Chutkan will decide which acts alleged in the indictment are official and which ones are unofficial. The official ones are presumptively immune, and the unofficial ones are bereft of protection from prosecution. 

The Supreme Court’s remand of Trump v. United States assigns to Judge Chutkan the task of deciding what chunks of Mr. Smith’s indictment can withstand the court’s freshly minted jurisprudence. Any decision she makes will in turn be subject to appeal to the United States Court of Appeals for the District of Columbia Circuit, and possibly the Supreme Court.

The special counsel will not have free rein when it comes to persuading Judge Chutkan that his charges are built on prosecutable actions. The high court has ruled that once an act is deemed official, not only can it not be charged, but it also cannot be used as evidence with respect to chargeable activities. It was on this point that Justice Amy Coney Barrett dissented from her conservative colleagues, to no avail. She wrote that the “Constitution does not require blinding juries to the circumstances surrounding conduct for which Presidents can be held liable.”

The January 6 case has been frozen pending the ruling from the Nine, which has now come down. When Judge Chutkan paused the case, she signaled to both sides that it would only resume when there was ample time to prepare. In February, Politico reported that Judge Chutkan shared that she hoped “not to be in the country on August 5,” though she acknowledged that could change if she was “in trial in another matter,” meaning the Trump trial. 

While there will be no trial before a jury this summer, the possibility of these “mini-trials” over immunity — or call it, say, the trials before the trial — could call Judge Chutkan back to the District of Columbia. Once on the bench, the jurist would be bound by the high court’s division between the “absolute” immunity granted for actions undertaken within the president’s core authority, the presumption of immunity for all official acts, and the lack of immunity for all official acts. 

A preview of what such proceedings could look like occurred during oral arguments in June, when Justice Coney Barrett quizzed Trump’s attorney, John Sauer, as to what acts in the indictment he could concede as private, and therefore not protected by immunity. Now, Chief Justice Roberts writes that “whether the communications alleged in the indictment involve official conduct may depend on the content and context” of each act.

As an appellate court — the highest in the land — the Supreme Court understands itself to be ill-equipped for the kind of muckraking that could be required to determine if, say, a particular conversation between Trump and Vice President Pence is immune or if the special counsel has met his burden. It will be Judge Chutkan’s job to “determine in the first instance whether this alleged conduct is official or unofficial.”

It is possible that Judge Chutkan will not be the only jurist holding a preliminary trial before a jury trial with respect to prosecutions of Trump. The 45th president has made the same request to Judge Aileen Cannon, in South Florida. Judge Cannon is presiding over the Mar-a-Lago documents case, also brought by Mr. Smith. There too Trump contends that immunity blocks his prosecution.