The U.S. Supreme Court’s ruling in North Carolina’s high-profile partisan gerrymandering case offered an excellent lesson about the limits of judicial power. It’s a lesson that should come in handy soon for state judges.

They will have to address similar arguments in a case scheduled to head to trial this month.

A three-judge state Superior Court panel hearing Common Cause v. Lewis convenes today in Raleigh. Plaintiffs challenge N.C. House and Senate election maps. They contend that Republican legislators used an overly partisan process when drawing those maps.

Today’s hearing addresses procedural issues. The full case is slated for trial July 15.

Before focusing on the potential impact of the U.S. Supreme Court ruling, it’s worth noting the wisdom of the three-judge panel’s scheduling decisions.

Left-of-center activist group Common Cause and the N.C. Democratic Party filed suit against the legislative election maps last Nov. 13, exactly one week after the 2018 general election. While no one expected an immediate trial, it’s likely that the competing parties could have prepared for a courtroom battle earlier this year.

Instead, state judges decided to wait. They learned Jan. 2 that a federal judge would not transfer Common Cause v. Lewis to the federal court system. Two days later, the U.S. Supreme Court announced its plan to hear arguments in March in a separate partisan gerrymandering case involving N.C. congressional districts. The high court’s Jan. 4 announcement almost certainly guaranteed a federal court ruling on the partisan gerrymandering issue by the end of June.

Armed with that information, state judges decided on Feb. 1 to give plaintiffs and defendants more than five months to prepare for this summer’s courtroom showdown. A July 15 trial date was guaranteed to give all parties — including the judges — more than two weeks to process the results of the federal case.

The three-judge panel did not need to wait for guidance from the nation’s highest court. Unlike the case that headed to Washington, Common Cause v. Lewis challenges election maps under provisions of the state Constitution. The map’s critics could argue that a federal ruling should have a limited impact on state court action.

That’s true. But both federal and state courts must wrestle with a common challenge: resolving the judicial branch’s proper role in determining just how much partisanship is “too much” when lawmakers draw election maps.

It’s not an easy issue. Judges decide legal disputes. They’re not supposed to pick winners and losers in partisan political battles.

Chief Justice John Roberts’ decision in the federal case, Rucho v. Common Cause, set a clear standard for federal judges’ role — none — in future partisan gerrymandering cases. Recognizing that North Carolina’s congressional election map is “highly partisan, by any measure,” Roberts nonetheless concluded for a 5-4 Supreme Court majority that judges cannot translate that high degree of partisanship into a clearly defined constitutional violation.

Trying to determine “fair” election districts involves “political, not legal” questions. “Federal courts are not equipped to apportion political power as a matter of fairness, nor is there any basis for concluding that they were authorized to do so,” the chief justice wrote.

“There are no legal standards discernible in the Constitution for making such judgments, let alone limited and precise standards that are clear, manageable, and politically neutral,” Roberts wrote.

Critics of the N.C. election maps and the Supreme Court’s four dissenting justices seek “an unprecedented expansion of judicial power,” the chief justice adds. “We have never struck down a partisan gerrymander as unconstitutional — despite various requests over the past 45 years. The expansion of judicial authority would not be into just any area of controversy, but into one of the most intensely partisan aspects of American political life.”

Roberts and his colleagues reject that proposed expansion of judicial authority. While their decision sends a clear message to federal judges, the potential impact for state courts remains less certain.

“Our conclusion does not condone excessive partisan gerrymandering,” Roberts writes. The chief justice then sets out ways Congress or the states can address the issue without federal judicial meddling.

He references independent mapmaking methods. (North Carolina has multiple options for taking that route.) Roberts also cites action from state courts, including the Florida Supreme Court’s decision to strike down a congressional election map in 2015.

The Florida case relied on a specific Fair Districts Amendment in that state’s constitution. Roberts writes that other states might have laws or constitutions with provisions that provide “standards and guidance for state courts to apply.”

Legislative leaders say N.C. courts already have set precedents on partisan mapmaking. Lawmakers contend those precedents bolster their legal case. “The N.C. Supreme Court has already ruled on considering politics after other criteria, writing that ‘the General Assembly may consider partisan advantage and incumbency protection in the application of discretionary redistricting decisions,’” said Sen. Ralph Hise, R-Mitchell, in a prepared statement issued shortly after Roberts’ decision.

It’s unclear whether the three-judge panel in Common Cause v. Lewis will agree. It might endorse instead the view expressed in Justice Elena Kagan’s dissent in the federal case. She wrote that Roberts and the court majority “goes tragically wrong” in washing its hands of partisan gerrymandering. The disputed maps “debased and dishonored our democracy, turning upside-down the core American idea that all governmental power derives from the people,” Kagan wrote.

But if the state three-judge panel concludes that some degree of partisanship in N.C. election mapmaking is “too much,” it must employ a clear legal standard. Otherwise, judges will be playing politics rather than settling law.

Having given themselves time to consider the opinion of the highest court in the land, state judges ought to keep Roberts’ concluding words in mind.

“It is emphatically the province and duty of the judicial department to say what the law is,” the chief justice wrote, quoting the landmark 1803 case of Marbury v. Madison. “In this rare circumstance, that means our duty is to say ‘this is not law.’”

Absent a clear legal standard based on the N.C. Constitution, state-level judges would face the same duty when addressing partisan gerrymandering. Rather than choose sides in a partisan fight, they could say “this is not law.”

Mitch Kokai is senior political analyst for the John Locke Foundation.