President-elect Trump’s request that the Georgia court of appeals dismiss the racketeering case brought against him and 18 others by the district attorney of Fulton County, Fani Willis, could soon lead to a clash at the Supreme Court between Ms. Willis and the president-elect.

The filing on Wednesday takes the form of a notice of jurisdictional issue to the Peach State appellate tribunal. Trump’s lawyer, Steven Sadow, asserts the “unconstitutionality of his continued indictment and prosecution by the State of Georgia in the case … now that he is President-Elect and will soon become the 47th President.”

Mr. Sadow contends that “a sitting president is completely immune from indictment or any criminal process, state or federal,” though no court has ruled on the specifications of that protection. The Department of Justice takes the position that there is a “categorical” imperative against prosecuting a president. That only binds federal prosecutors, like Special Counsel Jack Smith. 

The DOJ’s Office of Legal Counsel, which formulated that position, writes that the Constitution forbids “putting into the hands of a single prosecutor and grand jury the practical power to interfere with the ability of a popularly elected President to carry out his constitutional functions.” Trump reasons that applies to local prosecutors like Ms. Willis.

Mr. Sadow reaches back to what he calls “the dawn of the Republic” to cite Justice Joseph Story’s “Commentaries on the Constitution.” Story reasoned that “the president cannot … be liable to arrest, imprisonment, or detention, while he is in the discharge of the duties of his office.” 

The Georgia court of appeals last month canceled a hearing that was scheduled for Thursday to determine whether Ms. Willis is disqualified from the case on account of her secret romance with her handpicked special prosecutor, Nathan Wade. No reason was given, and Ms. Willis could yet be removed. She has given no indication, though, that she intends to change course after Trump’s victory over Vice President Harris last month. 

In requesting dismissal, Trump contends that such a course is mandated by the Constitution’s Supremacy Clause, which ordains that federal law is part of “the supreme law of the land” and therefore trumps state law — like Georgia’s criminal code. He also cites the principles of federalism and comity to persuade the appeals court to drop the charges. 

The Supreme Court has a long history of defending federal prerogative. As far back as McCulloch v. Maryland, in 1819, it averred that states “have no power … to retard, impede, burden, or in any manner control, the operations” of the federal government. In 1924, it reckoned that “the Constitution guarantees ‘the entire independence of the General Government from any control by the respective States.’”

Mr. Sadow also adduces “compelling evidence of local bias and political prejudice against the President by the local prosecutor, who not only answers to a tiny segment of the American electorate but is acting in clear opposition to the will of the citizens of Georgia as reflected by the recent election results.” If Trump loses before the court of appeals, he could appeal to the Georgia supreme court — and, possibly, the highest court in the land. 

Ms. Willis has accused her defendants of “playing the race card,” and insists that the “train is coming” to convict Trump and his co-defendants. Trump won Georgia last month by a little more than two percentage points. That outcome was likely particularly gratifying to him, as Ms. Willis’s case is built on his actions to reverse the result of the 2020 election in the state, which he lost to President Biden.

Ms. Willis, though, also won her election last month, suggesting that Fulton County approves of her prosecution of the president-elect. Yet the district attorney suffered a setback on Tuesday when a jury acquitted of murder two members of the YSL gang. A judge also ruled that she violated Georgia’s open records statute by failing to fulfill a request to hand over records related to her office’s communication with Mr. Smith and House Democrats.