(AP) — A U.S. Supreme Court case involving North Carolina’s congressional districts could have ramifications for the way voting districts are drawn in other states, including Ohio. 

At issue in today’s arguments is whether state courts can strike down U.S. House maps passed by state lawmakers for violating state constitutions. North Carolina’s Republican legislative leaders are asserting an “independent state legislature” theory — claiming the U.S. Constitution gives no role to state courts in federal election disputes. The outcome could affect similar lawsuits pending in state courts in Kentucky, New Mexico and Utah. It also could have implications in New York and Ohio, where state courts previously struck down U.S. House districts.

Partisan gerrymandering is back before the U.S. Supreme Court in a case stemming from the latest attempt by North Carolina’s Republican-led legislature to draw U.S. House districts favoring GOP candidates.

The question justices will consider today is whether state courts can rely on their state constitutions — as the North Carolina Supreme Court did — to strike down politically rigged voting districts for congressional elections.

North Carolina’s top Republican lawmakers contend they can’t. Rather, they assert that the U.S. Constitution gives power over federal elections only to state legislatures and Congress — an argument known as the “independent state legislature” theory. A broad embrace of the theory by the high court could upend hundreds of election laws across the U.S.

A ruling for North Carolina’s legislature also could affect redistricting lawsuits in states ranging from Republican-led Ohio to Democratic-led New Mexico. It also could call into question new congressional maps enacted by other state courts after the 2020 census.

The stakes are high because Republicans won only a slim House majority in the November elections, giving them just enough power to challenge President Joe Biden’s agenda. Any ruling that causes some districts to be redrawn likely would kick in for the 2024 elections.

WHAT IS GERRYMANDERING?

Gerrymandering is when a political party in power manipulates voting district boundaries to make it harder for the opposing party to win. That typically is done by packing opponents’ voters into a few districts and spreading out others among multiple districts to dilute their voting strength.

Throughout U.S. history, both Republicans and Democrats have gerrymandered after the once-a-decade census, when districts are redrawn to account for population changes.

Republicans controlled more state capitols after the 2010 census and used redistricting to their advantage, prompting a flurry of lawsuits from Democrats. Those suits culminated in 2019, when the U.S. Supreme Court ruled in another North Carolina case that federal courts have no role in deciding partisan gerrymandering disputes. Even so, the majority opinion suggested that state courts still could hear such claims.

Freed from federal constraints, partisan gerrymandering surged after the 2020 census. So did the number of lawsuits in state courts alleging that partisan gerrymandering violated state constitutions.

The outcome of the North Carolina case also could have implications for Ohio.

Ohio’s Supreme Court twice ruled that Republicans who control the redistricting process violated a voter-approved constitutional provision against unduly favoring political parties. But the 2022 election went forward anyway using the stricken districts as Republicans appealed the decision to the U.S. Supreme Court.

It’s unclear whether the nation’s high court will take up the Ohio case. But a decision in favor of North Carolina’s GOP lawmakers could pave the way for Ohio’s Republican officials to ignore their own court’s directives.

Earlier this year, New York’s highest court struck down congressional districts enacted by the Democratic-led Legislature after an independent commission failed to agree on a plan. The court said lawmakers violated a voter-approved state constitutional prohibition against favoring particular political parties. A judge then imposed new U.S. House districts for the 2022 election that were not as skewed toward Democrats.

A ruling for North Carolina’s Republican lawmakers could create an avenue for New York Democrats to argue that state judges had no authority to throw out the map they originally passed and impose a new one.

Some conservative lawyers have urged the high court to issue a comparatively narrow ruling that would still allow state courts to overturn maps in states such as New York, where voters have explicitly approved anti-gerrymandering initiatives.

A Maryland court this year also ruled that the U.S. House map passed by the Democratic-led Legislature was an “extreme gerrymander” that violated state constitutional requirements for compact districts and “free” elections. But the court never imposed a new map. Instead, lawmakers worked with the outgoing Republican governor to enact a new map. Democrats will have full control of state government when the new governor is sworn in next month.