A governor cannot use his veto power to render the Legislature unable to function. So said the chief judge of Ramsey County District Court on Wednesday as he rejected Gov. Mark Dayton's line-item veto of the Legislature's 2018-19 operating budget — a veto DFLer Dayton said he made in hopes of compelling the Republican-controlled Legislature to agree to smaller tax cuts than Dayton had already signed.

That's not the final legal word on the subject. Dayton said soon after the order was issued that he will press his defense of his veto — and of his office's veto power — to the Minnesota Supreme Court.

We hope he does, and soon. The questions about gubernatorial authority raised by Dayton's unconventional use of his veto power deserve answers with the clarity and finality that only the state's highest court can provide.

Ramsey County Chief Judge John Guthmann evidently shares that view. "The prompt and final resolution of any appellate issues" raised by his order "will be in the best interest of the parties to this action and the state of Minnesota," Guthmann wrote in his order.

But to Guthmann's credit, his order did not shrink from the constitutional question that would likely be the high court's focus as well: Is it constitutionally permissible for one branch of state government to abolish another? That, in essence, is what Dayton's veto did, Guthmann concluded, as he answered the question with a firm "no." He saw the dispute not as a political spat for the other two branches of government to resolve among themselves, but as a challenge to the separation of powers principle in the state Constitution.

Dayton argues that the cuts included in the 2017 tax bill are too large. Those cuts are forecast to take an ever-bigger bite out of state revenues in future years, which will jeopardize the state's financial stability, he says. But defunding an entire branch of government as a "tool of … coercion" goes out of constitutional bounds, Guthmann argued. Minnesotans ought to know soon whether the seven Supreme Court justices agree.