A federal judge has quashed six grand jury subpoenas the Trump administration served against Minnesota state and local government offices — including Gov. Tim Walz and Minneapolis Mayor Jacob Frey — ruling the subpoenas were retaliatory and unlawful.

U.S. District Judge Patrick Schiltz found that the Justice Department issued the subpoenas to coerce Minnesota officials into cooperating with immigration enforcement after those officials sued to block Operation Metro Surge, a federal immigration operation.

The subpoenas had been served against the Minnesota governor's office, the Minnesota attorney general, two Minnesota mayors' offices, Ramsey County's Board of Commissioners and Hennepin County's Board of Commissioners.

In his ruling, Schiltz wrote that using grand jury proceedings to pressure political opponents into taking official action — particularly action the federal government cannot directly require — is "a blatantly unlawful and unethical use of the grand-jury process."

"The only question, then, is whether the challenged subpoenas were issued for one of these forbidden purposes," Schiltz wrote. "The Court has no doubt that they were."

The judge also noted that the Justice Department "has struggled — without success — to identify a single plausible investigatory justification for the subpoenas."

The ruling centers on Operation Metro Surge, a Trump administration immigration enforcement effort that prompted Minnesota state and local officials to file suit in an attempt to stop it. The subpoenas followed that legal challenge.

A spokesperson for the Department of Justice did not immediately respond to a request for comment.