MADISON, Wis. (AP) — The Wisconsin Supreme Court is set to hear oral arguments Wednesday in a lawsuit that will determine whether the state schools superintendent or the governor controls K-12 public education policy.

Republicans have been trying for years to reduce the superintendent’s powers. The position is officially nonpartisan but liberal-leaning superintendents have controlled the office for nearly two decades.

The Wisconsin Institute for Law and Liberty, a conservative law firm, filed a lawsuit in 2017 alleging that a new law requiring state agencies to obtain the governor’s permission before writing rules, regulations and policies applies to the superintendent.

The firm filed the suit when now-Gov. Tony Evers, a Democrat, was state superintendent and in the throes of a campaign against then-Republican Gov. Scott Walker. The post is now held by Carolyn Stanford Taylor, whom Evers appointed as his replacement. A ruling that the superintendent can’t create policy without the governor’s permission wouldn’t help the GOP immediately, but it would give the party de facto control of the office should a Republican defeat Evers in the future.

Institute attorney Rick Esenberg said the case is about the law, not politics.

“The (Wisconsin) Constitution gives the legislature the authority to decide if and how it will allow agencies to make rules,” Esenberg said in an email to The Associated Press. “That constitutional authority ought to be recognized and upheld no matter who the Governor happens to be.”

At the heart of the case is a law Republicans passed in the summer of 2017 nicknamed the REINS Act. The measure requires agencies to obtain permission from both the governor and the Department of Administration, which the governor controls, to write regulations and administrative rules that enact policy and statutes. The institute filed a lawsuit directly with the state Supreme Court in November of that year alleging Evers, then the superintendent, wasn’t complying with the act and asked for a declaration that the requirement applies to that office.

“All rules must be based on an express grant of rule-making authority by the Legislature,” Esenberg argued in his November 2017 filing asking the Supreme Court to take the case. “The Legislature commands the process to be followed in exercising this authority.”

Attorneys for both Evers and the state Department of Public Instruction countered that the court decided years ago that the superintendent doesn’t need the governor’s approval to write regulations.

The court ruled 4-3 in 2016 that a law Republicans passed in 2011 requiring state agencies to obtain the governor’s approval before promulgating regulations didn’t apply to the superintendent because it’s a separate constitutional office elected by the people. Evers and DPI’s lawyers maintain the REINS Act simply duplicates the 2011 law and therefore can’t affect the superintendent.

“Since statehood, the supervision of public instruction has been vested in an independent, constitutional officer,” they argued in court filings.

Two justices who found the 2011 law doesn’t apply to the superintendent — Michael Gableman and David Prosser — have since left the court. But conservatives still maintain a 4-3 majority.