Judges are typically loath to wade into disputes between the executive and legislative branches of government. That reluctance is generally advisable. It helps the courts maintain the reputation for impartiality and independence that public trust requires.

That said, we hope the justices of the Minnesota Supreme Court aren't looking for a way to avoid the questions raised in the line-item veto lawsuit involving the Legislature and Gov. Mark Dayton, which was the subject of oral arguments on Monday. That case and another on the high court's docket this fall involving the state auditor's office present chances to reinforce the constitutional boundaries of a lawmaking process that has lately taken unprecedented and dubious turns.

Never before have observers seen a governor line-item veto the operating budget for the House and Senate, not because the governor deemed that budget too large, but because he wanted to force legislators back to the bargaining table on other matters. Never before have Minnesotans seen a Legislature inject into a spending bill a measure defunding the entire Revenue Department, should the governor veto another bill laden with tax cuts.

Characteristically, the six justices hearing the case involving Dayton's line-item veto did not tip their hands Monday about how they will rule. Their decision will come "in due course," Chief Justice Lorie Skjerven Gildea said. The temporary agreement that is keeping legislative paychecks flowing is set to expire on Oct. 1.

The justices' questions Monday revealed awareness that this case is as much about the role of the courts as it is about gubernatorial and legislative authority. Attorneys for both Dayton and the Legislature said they look to the judicial branch to rescue the state from untenable consequences arising from their budget dispute. "The judiciary is the safety valve," Dayton attorney Sam Hanson said. The justices countered by voicing unwillingness to become more involved in state taxing and spending decisions. Associate Justice Natalie Hudson fretted about "institutionalizing the situation" in which state budget disputes are resolved by the courts. Gildea noted that the Minnesota Constitution "tells us who has the authority to appropriate money, and it's not the judiciary."

True enough. But the judicial branch is the ultimate interpreter of the state Constitution. It alone can determine whether the DFL governor's unprecedented use of the line-item veto is constitutionally permissible. In the case involving the funding for the state auditor's office, the courts alone can decide when defunding a constitutionally created state office and/or when bundling policy provisions into a difficult-to-veto spending bill are abuses of the Constitution.

The justices may not like having to rule in two cases that are bound to cast them in a partisan light, no matter how they come down. But for the sake of restoring customary order to a lawmaking process that recently has witnessed power grabs by both the executive and legislative branches, the justices ought not shrink from their duty to decide.