The dismissal of three of the criminal charges handed up against President Trump at Fulton County is the latest sign that District Attorney Fani Willis’s case against the 45th president is in freefall.

The ruling came from Judge Scott McAfee, who has presided over the racketeering case that alleges a criminal enterprise to overturn the result of the 2020 presidential election in Georgia. Of the 41 charges first brought against Trump and his allies, nine have now been nullified. In March, Judge McAfee found six to be tainted with vagueness, which impairs a defendant’s right to fair notice.

Judge McAfee deemed the three charges he dismissed Thursday — filing false documents, attempting to file false documents, and criminally conspiring to file false documents — to be federal matters, not crimes that Fulton County could prosecute. Of the 13 charges Trump originally faced in the case, only eight survive. Judge McAfee, though, demurred from dismissing the case altogether.

The judge’s ruling is a validation of Trump’s contention that he is protected from state and federal prosecution by the prerogative of the office he once held. Another one of Ms. Willis’s defendants, Chief of Staff Mark Meadows, has made a similar argument to the Supreme Court in an effort to remove his case to federal court. Trump and Mr. Meadows both maintain that the district attorney’s case encroaches on federal power.

Now Judge McAfee has determined that Ms. Willis has, with respect to at least some of her charges, acted crosswise with the Constitution. Trump, Mr. Meadows, and the other defendants will likely attempt to leverage this finding to whittle down the case further. Expect the 45th president to soon mount a challenge on the basis of the Supreme Court’s landmark immunity ruling in Trump v. United States, which granted presumptive immunity for all official presidential acts.

Mr. Meadows first raised a defense grounded in the Supremacy Clause more than a year ago, but has so far not found success before Judge McAfee and the 11th United States Appeals Circuit. That part of the parchment ordains in part  that the “Laws of the United States … shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.”

While Judge McAfee did not agree that Ms. Willis’s case “is inseparably connected to the functioning of the national government,” he does find that the Constitution “preempts the State’s ability to prosecute perjury and false filings in a federal district court.” Those charges now “must be quashed,” notwithstanding Ms. Willis’s contentions that her accusations are rooted in violations of Peach State law. 

Georgia law demands that a judge find a “clear and palpable” conflict between state law and the constitution to rule that the former is invalid. The Supreme Court has ruled, though, that “States may not impose their own punishment for perjury in Federal Courts,” meaning that the swath of Ms. Willis’s indictment that charges the submission of false statements to federal courts has to go because  “Georgia does not have a ‘legitimate interest’ and jurisdiction to punish such statements.”

Judge McAfee applauds Ms. Willis’s “tenacious” effort to extend Fulton County’s authority but insists that “federal laws provided — and still provide — a mechanism of enforcement against false statements made under oath in judicial proceedings.” Ms. Willis’s challenges, though, go beyond what Judge McAfee describes as  a “consideration of dual sovereignty” — federal and state. 

The district attorney is seeing her indictment shrink as her own role in the case comes under growing scrutiny. The Georgia Court of Appeals has set a date in December for oral arguments to determine whether Ms. Willis ought to be disqualified for her secret romance with her handpicked special prosecutor, Nathan Wade. Trump et al. also argue that her accusation that her opponents are “playing the race card” amounted to a poisoning of the jury pool in majority-minority Fulton County, which comprises much of downtown Atlanta. 

Ms. Willis faces challenges not only from the bench but also from Georgia lawmakers. She plans to defy a pair of subpoenas issued by a state Senate committee — controlled by Republicans — and contends that the summonses are improperly issued and overly broad. The Senate Special Committee on Investigations demanded her testimony at a Friday morning hearing as well as the provision documents adumbrating her romantic relationship with Mr. Wade. 

Ms. Willis’s attorney, the former governor Roy Barnes, tells the Atlanta Journal-Constitution that Ms. Willis “will not appear until there has been a judicial determination of the validity of the subpoena.” The lawmaker, Bill Cowert, who leads the subcommittee that issued the subpoenas, declares that he is very disappointed that an elected official such as Ms. Willis, who is elected to enforce the law, believes that she is above it.”