RALEIGH — North Carolina’s highest court for the first time is wading into the long-running effort by Republican legislators to strip away as many powers as possible from Democratic Gov. Roy Cooper.

The state Supreme Court hears arguments Monday in a lawsuit brought by Cooper that claims the GOP-controlled legislature violated the constitution when it passed a law diminishing the governor’s role in managing elections. Cooper’s lawsuit is part of the ongoing political battle that began after he narrowly beat incumbent GOP Gov. Pat McCrory last November. GOP lawmakers have sought to defang Cooper’s powers ever since.

Last spring, the legislature voted to upend a law that for a century had given the governor and his or her political party the majority on local and state boards that oversee elections. Cooper then sued.

“The actions of Legislative Defendants over the past nine months and its arguments in these proceedings demonstrate that they consider separation of powers to be a mere guideline or suggestion that places no substantive constraint on the laws they may pass,” Cooper’s lawyers wrote in pre-trial briefs. “The legislature is not ‘more equal’ than its coordinate branches. It is not superior. It is not above the law.”

The new law converts the State Board of Elections and all 100 county elections boards from having a majority of Democrats on panels with odd numbers of members to having boards with equal numbers of Republicans and Democrats. The law also prevents the state’s top elections executive, a Republican, from being removed from her job for years. It also directs a Republican to be the chairman of the new elections board with broader scope in even-numbered years, when national and statewide contests generate the most voter interest.

County elections boards handle such things as voter registration and location of polling places. Disagreements that can’t be settled locally are decided by the state board, which also investigates claims of voter fraud and enforces campaign finance laws.

A three-judge panel ruled unanimously in June it wasn’t up to them to settle the lawsuit pitting the governor against legislative leaders. Attorneys for state House Speaker Tim Moore and Senate leader Phil Berger think the Supreme Court should also butt out of what is essentially a political, not legal, dispute.

“The courts are not the proper forum in which to raise arguments about the wisdom of the General Assembly’s alteration of the structure of state agencies and the political make-up of a state board,” lawyers for Berger and Moore wrote.

They also argue that the dispute isn’t about the ability of citizens to vote in free, fair and orderly elections as Cooper’s side claims, but about which branch of government controls the makeup and functions of state agencies.

Cooper also has sued to block a law giving civil service job protections to McCrory’s political appointees. Cooper also went to court to void a law giving the wife of McCrory’s chief of staff a nearly 8½-year term paying more than $125,000 a year on the state’s Industrial Commission, a quasi-judicial panel that rules in workers’ compensation cases.

After Cooper saw some success challenging the GOP laws in court, lawmakers essentially blocked the governor from using taxpayer dollars to hire private lawyers. Lawmakers also took away Cooper’s ability to fill upcoming appeals court vacancies and cut his operating budget.