Advanced by North Carolina’s Republican legislative leaders, the “independent state legislature theory” could negate a governor’s veto, end the oversight of courts enforcing the state constitution and cast doubt on citizen-implemented initiatives aimed at taking partisan politics out of map-drawing and election rules.

If the argument is revolutionary, it is also simple. The leaders wrote in a brief to the court that the Constitution “assigns state legislatures the federal function of regulating congressional elections. . . . Because this directive is supreme over state law, the States may not limit the legislature’s discretion.”

But the Supreme Court has never ruled that the Constitution’s recognition that the legislature leads the process should replace the normal mechanisms of government, in which legislators are constrained by the state constitution and overseen by state courts. Part of the argument Wednesday will center on the meaning of the word “legislature” in the Founding Fathers’ minds.

The Supreme Court thrives on hypotheticals. Alito’s latest sparked backlash.

The importance of the case is magnified by the nation’s polarized and disruptive political landscape, with hundreds of election-deniers seeking public office and former president Donald Trump and his allies waging lengthy battles to undermine confidence in and reverse the results of the 2020 election. Last month’s elections showed that control of Congress can depend on the manipulation of a handful of congressional district lines. Polls show record Democratic distrust of a Supreme Court dominated by justices nominated by Republicans.

A study by the liberal Brennan Center for Justice said that accepting North Carolina’s argument, which is supported by other Republican-led states, would endanger hundreds of state constitutional provisions and state court decisions and more than a thousand delegations of authority to officials, commissions and others.

And because there is a similar reference to “legislature” in an accompanying provision of the U.S. Constitution regarding presidential elections, the stakes are even higher, the center’s report said. “The nightmare scenario is that a legislature, displeased with how an election official on the ground has interpreted her state’s election laws, would invoke the theory as a pretext to refuse to certify the results of a presidential election and instead select its own slate of electors.”

Law professor John Eastman, representing Trump in post-election challenges in 2020, advanced just such a theory.

Moore v. Harper challenges the North Carolina Supreme Court’s decision to replace a partisan congressional map with one judges found more in tune with the state constitution’s guarantee of free elections. It has drawn enormous and strident interest — mostly from critics warning the justices they are about to make a big mistake. Only 16 of the nearly 70 amicus briefs filed with the Supreme Court side with North Carolina’s legislative leaders.

The opposition includes not only includes civil rights organizations and Democratic-led states but also the chief justices of the nation’s state supreme courts; credentialed, retired Republican judges; the co-founder of the conservative Federalist Society; former California governor Arnold Schwarzenegger; and Republican election lawyer Ben Ginsberg — who, in the words of the Brennan Center report, “worked in the Bush v. Gore case that planted the seeds of the theory” that forms the backbone of the challenge.

“This case is nothing less than a direct challenge to our system of checks and balances. It’s truly a fringe, fringe theory,” said Eric H. Holder Jr., who served as attorney general under President Barack Obama.

“Fringe” is a word ubiquitous in the filings. But four of the nine Supreme Court justices have already expressed interest in — if not outright support for — the state-legislature theory. Which raises the question: How much of an outlier can it be?

In the aftermath of the disputed 2000 presidential vote, Justice Clarence Thomas joined a concurring opinion in Bush v. Gore by then-Chief Justice William H. Rehnquist that said the Constitution’s grant of power to legislatures to oversee elections limited the power of state judges to intervene. Justice Antonin Scalia was the only other member of the court to sign on.

The doctrine comes from the U.S. Constitution’s election clause, which says that the “Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof.” There is similar language regarding presidential electors.

In the past, the language has been widely interpreted as bestowing the power on states, shared by citizens and the legislative, executive and judicial branches.

But in voting disputes leading up to the 2020 presidential election, Thomas and Justices Samuel A. Alito Jr., Neil M. Gorsuch and Brett M. Kavanaugh expressed varying degrees of support for the view that state courts could not usurp the role of state legislatures in prescribing rules for federal elections.

When North Carolina’s GOP leaders asked the U.S. Supreme Court to block the imposition of the court-ordered congressional map, a majority of justices refused. But Alito, Thomas and Gorsuch dissented, saying the legislature seemed to have the better argument.

“If the language of the Elections Clause is taken seriously, there must be some limit on the authority of state courts to countermand actions taken by state legislatures when they are prescribing rules for the conduct of federal elections,” Alito wrote. “I think it is likely that the applicants would succeed in showing that the North Carolina Supreme Court exceeded those limits.”

In challenges to voting rules changed by courts, other justices expressed similar views. “The Constitution provides that state legislatures — not federal judges, not state judges, not state governors, not other state officials — bear primary responsibility for setting election rules,” Gorsuch wrote in a case from Wisconsin.

Chief Justice John G. Roberts Jr. was a dissenter when the Supreme Court ruled in 2015 that Arizona citizens could place the power to redraw districts in an independent commission. He accused the majority of using a “magic trick” to impose its policy preferences by interpreting “legislature” to mean the citizens of the state.

But in 2019, when deciding partisan gerrymandering was outside of the purview of federal courts, Roberts and other conservative justices said state courts could ensure the process did not become so extreme as to impinge on the rights of voters.

“Provisions in state statutes and state constitutions can provide standards and guidance for state courts to apply,” their opinion said.

A history of gerrymandering

It is fitting that the high-stakes battle over elections authority comes from North Carolina. It is a purple state, with a legislature controlled by Republicans, a Democratic governor and attorney general and a partisan, elected state Supreme Court that in November flipped to the GOP. Trump won 50 percent of the vote in 2020, compared with 49 percent for Joe Biden.

North Carolina Common Cause Executive Director Bob Phillips said there has not been an election since 1971 in which the state’s redistricting plans have not been challenged.

“In the decade after the 2010 redistricting cycle, every single legislative and congressional election was run on maps that the courts eventually ruled unconstitutional,” he said in a briefing for reporters. “I’m not sure there are many states, if any, that can make that claim.”

Analysts said the map created by Republican legislators after the 2020 Census would have given the GOP an edge in 10 of 14 congressional districts.

The court, which at the time had a Democratic majority, concluded the maps “are unconstitutional beyond a reasonable doubt under the free elections clause, the equal protection clause, the free speech clause, and the freedom of assembly clause of the North Carolina Constitution.”

Under a new map imposed just for the 2022 election, the congressional delegation is split 7 to 7.

“It’s almost unfathomable to imagine what will be imposed on North Carolina citizens if our state courts are no longer a place where a bad congressional map can be challenged,” Phillips said.

North Carolina’s legislature set up a stem for judicial review of redistricting challenges, which could also be a factor in this case.

Lee Goodman, a former Federal Election Commission chairman who filed a friend-of-the-court brief for the conservative American Legislative Exchange Council, said the founders of the country were explicit in saying election rules were the responsibility of legislatures and not other parts of state governments.

“When the Founders assigned the responsibility of drawing rules for elections, including drawing district lines, they had to assign the role to somebody or some institution,” he said in an interview this week. “The Constitution could have assigned it to the states, but the Constitution specifically assigned the duty to the legislatures of the states — with a check by Congress.”

John Yoo, a University of California at Berkeley law professor, agreed that in such situations, state legislators were not governed by state constitutions.

“When the [U.S.] Constitution uses the state legislature here, it’s actually commandeering the state to perform a federal function,” he said in an interview. “It’s as if the state legislature becomes part of the federal government for that one purpose.”

He contended the same logic held in a 1995 case that found states could not impose term limits on members of Congress.

Such views are contradicted in briefs from the other side.

“Every Justice should exercise extreme caution before accepting any of Petitioners’ assertions,” says a brief by legal scholars (and brothers) Akhil Reed Amar and Vikram David Amar along with Steven Calabresi, one of the co-founders of the Federalist Society. “Their brief is littered with major misstatements and half-truths.”

The scholars argue that the public meaning of “legislature” was clear “at the time of ratification: A state’s ‘legislature’ was not just something created to make laws on behalf of the people; it was something created and constrained by the state constitution.”

They add, “This basic starting point — that state legislatures were creatures of state constitutions, creatures whose very existence and shape derived from state constitutions — suffices to defeat” the independent state legislature theory.

Patrick Marley in Madison, Wis., contributed to this report.