Supreme Court hears case that could reshape US election laws

The Supreme Court on Wednesday will hear arguments in a case that experts say could dramatically alter how elections are run in the U.S.

Moore v. Harper focuses on a dispute in North Carolina over redistricting after a voting map created by the Republican-led state legislature was struck down as violating the state constitution and then replaced by court-appointed experts.

The justices this term will consider the state legislature's appeal to reinstate their gerrymandered maps. North Carolina Republicans contend state courts don't have the power to take action.

At the center of their case is a controversial legal concept called the "independent state legislature theory," which contends that state legislators alone have the power to govern federal elections unencumbered by traditional oversight from state constitutions, courts and governors.

The concept, if embraced by the justices in its most extreme application, could upend election laws across the country, experts previously told ABC News -- all before the 2024 presidential election.

At stake, the experts said, are thousands of laws governing everything from voter registration rules to ranked-choice voting systems and even the designation of presidential electors.

"At its core, this appeal is a dangerous and extreme attempt to eliminate accountability for state legislatures interested in gerrymandering with impunity," Marina Jenkins, a director at the National Redistricting Foundation, said in a statement ahead of this week's oral arguments.

Kathay Feng, the national redistricting director for Common Cause, contended that the case threatens to allow the manipulation of elections by politicians. Common Cause was at the center of a Supreme Court case in 2019 on the issue of partisan gerrymandering, in which the justices ruled that state courts and constitutions were a means of regulating gerrymandering in congressional elections.

"No one branch of government should have outsized power in America's system of government, and bucking this long-held tenet of our democracy would undermine people's ability to freely vote and shape the future of our communities and our country in a way that reflects the people's will," Feng said in a statement.

The conservative-aligned groups and lawmakers promoting the theory have a different view.

Jason Snead, the executive director of the Honest Elections Project, which filed an outside amicus brief in Moore v. Harper in support of the theory, told ABC News a ruling in their favor would be a victory "for voters who want fair rules" passed by elected officials.

"I think if if you do want to have fair elections run by rules that are passed by the democratic process, then you should be rooting for North Carolina legislators," Snead said.

Snead also asserted that state legislatures, under the independent legislature theory, would still be required to follow Congress and the U.S. Constitution. "There are checks and balances that would absolutely remain," he said.

Four members of the court's conservative wing -- Justices Samuel Alito, Neil Gorsuch, Brett Kavanaugh and Clarence Thomas -- have indicated an openness to the theory.

Oral arguments in Moore v. Harper will begin at 10 a.m. ET. The Supreme Court is expected to hand down a decision in June.

ABC News' Devin Dwyer contributed to this report.