“The most important case for American democracy” in the nation’s history — that’s how the former appeals court judge J. Michael Luttig described Moore v. Harper, an extraordinary lawsuit that the Supreme Court considered in oral arguments Wednesday morning. Judge Luttig, a conservative and a widely respected legal thinker, is not one for overstatement. Yet most Americans aren’t paying attention to the case because it involves some confusing terminology and an arcane legal theory. It is essential that people understand just how dangerous this case is to the fundamental structure of American government, and that enough justices see the legal fallacies and protect our democracy.First, the back story on the case: In 2021, North Carolina lawmakers redrew their congressional maps. The state had 13 districts at the time, and its voters were more or less evenly divided between Democrats and Republicans. But the Republicans who are in control of North Carolina’s legislature didn’t want fair maps; they wanted power. In one of the most egregious gerrymanders in the nation, they drew 10 seats intended to favor themselves.The North Carolina courts were not amused. A panel of three trial judges found that the 2021 maps were “intentionally and carefully designed to maximize Republican advantage” — so much so that Republicans could win legislative majorities even when Democrats won more votes statewide. The State Supreme Court struck down the maps, finding they violated the North Carolina Constitution’s guarantees of free elections, free speech, free assembly and equal protection.That should have been the end of it: A state court applying the state Constitution to strike down a state law. But North Carolina’s Republican lawmakers appealed, arguing that the U.S. Constitution does not give state courts authority to rule on their congressional maps — even though the legislature had passed a law authorizing the courts to review redistricting plans like these. Instead, the lawmakers are relying on an untested theory that asserts that state legislatures enjoy nearly unlimited power to set and change rules for federal elections.In 2000 the chief justice at the time, William H. Rehnquist, proposed the idea in his concurring opinion on Bush v. Gore, and the independent state legislature theory has been floating around the fringes of right-wing legal circles ever since.To be clear, this is a political power grab in the guise of a legal theory. Republicans are trying to see if they can turn state legislatures — 30 of which are controlled by Republicans — into omnipotent, unaccountable election bosses with the help of the conservative supermajority on the Supreme Court. The theory has no basis in law, history or precedent. The idea that state lawmakers exist free of any constraints imposed by their constitution and state courts makes a mockery of the separation of powers, which is foundational to the American system of government. By the North Carolina lawmakers’ logic, they possess infinite power to gerrymander districts and otherwise control federal elections. It is a Constitution-free zone where no one else in the state — not the governor, not the courts, not the voters through ballot initiatives — has any say.On Wednesday morning, Justice Elena Kagan rejected the theory out of hand, saying it “gets rid of the normal checks and balances on the way big governmental decisions are made in this country. And you might think that it gets rid of all those checks and balances at exactly the time when they are needed most.”In practice, the theory that the petitioners in the case are seeking to use would turn hundreds of state constitutional provisions into dead letters in federal elections. For instance, 48 states affirmatively guarantee a right to vote in their constitutions. (The federal Constitution still does not.) Most state constitutions guarantee free, fair, equal or open elections. Even the secret ballot — so fundamental to American democracy — is a creature of state constitutions. If the justices accept the most aggressive version of the independent state legislature theory that the petitioners want them to and even if they accept a weaker version, provisions like these could become invalid overnight, because the theory holds that state constitutions have no authority to impose any regulations on federal elections. (The Constitution and federal law remain supreme, so challenges to state legislative actions could still be brought in federal courts.)Some of the justices insist that they don’t — they can’t — pay attention to the real-world outcomes of their rulings. They’re just interpreting law. By that logic, this case should be rejected on its merits.First, the theory is based on bad legal interpretation. The Constitution uses the word “legislature” in describing who has the power to regulate federal elections. Because of this word, the theory’s supporters claim, state legislatures have nearly unlimited power in that realm. But as Judge Luttig has noted, the theory has “literally no support” in the Constitution. To the contrary, the framers who wrote the Constitution were concerned that state legislatures had too much power, not too little. The text they wrote makes many references to the powers of those legislatures and of Congress, but it never says or implies that they are immune to review by the judicial branch.Second, the theory is based on bad history. The best evidence its supporters offer is a two-century-old document that has long been known to be fraudulent. Written in 1818 by Charles Pinckney of South Carolina, a founding father, it is purported to be a replica of the plan for government that he introduced three decades earlier at the Constitutional Convention. But what he submitted in 1818 was not the real deal. James Madison suspected this immediately, as have virtually all historians to examine it in the years since.When the theory’s supporters sought to claim that the practices of early state legislatures proved that their side should win, Justice Sonia Sotomayor responded, “Yes. If you rewrite history, it’s very easy to do.”Third, if the Supreme Court accepts this theory, it will create a logistical nightmare in states across the country. That’s because the theory applies only to federal elections, not state elections, in which state courts unquestionably have a role to play. As a result, there would be two sets of rules operating at the same time, one for federal elections and one for state elections. Chaos and confusion would reign.Most important, the Supreme Court has already implicitly rejected the theory many times over. In precedents stretching back decades, the court has made clear that state courts have the power to set limits on what lawmakers can do when it comes to federal elections. As recently as 2019, the court rejected a plea for it to stop the extreme partisan gerrymandering in North Carolina and other states. In doing so, Chief Justice John Roberts explained that this is exactly the role that state courts should play. “Provisions in state statutes and state constitutions can provide standards and guidance for state courts to apply,” he wrote.At Wednesday’s argument, Justice Samuel Alito appeared to reject that premise. He accused elected state court judges, like those in North Carolina, of being political actors themselves. “There’s been a lot of talk about the impact of this decision on democracy,” said Justice Alito, who has given openly partisan speeches to outside groups and voted consistently in alignment with Republican policy priorities. “Do you think that it furthers democracy to transfer the political controversy about districting from the legislature to elected supreme courts where the candidates are permitted by state law to campaign on the issue of districting?”Another way to appreciate the absurdity of the theory is to consider who has come out for and against it. On one side, a large and bipartisan group of judges, government officials, former lawmakers, leading historians and constitutional scholars from across the political spectrum have rejected it. These include a co-founder of the right-wing legal group the Federalist Society, the chief justices of all 50 states, multiple Republican former governors and secretaries of state and civil rights organizations.On the other side, you will find a far smaller and less bipartisan cast of characters — among them, the Republican National Committee, a group of Republican state attorneys general and John Eastman, a former law professor last seen helping Donald Trump plan an illegal and unconstitutional coup to stay in office (an act that has exposed Mr. Eastman to a real risk of criminal prosecution).That so many justices would take the theory seriously is bad enough. Three of them — Justices Alito, Neil Gorsuch and Clarence Thomas — appear to favor the independent state legislature theory, as they suggested in an opinion in an earlier stage of the case. Justice Brett Kavanaugh has also indicated his openness to it. It’s worse when the public trust in and approval of the court have fallen to historic lows, thanks largely to aggressively partisan recent opinions, as this board has argued.There’s an old saying that only close cases make it to the Supreme Court. If they weren’t close, they would have been resolved in the lower courts. But Moore v. Harper isn’t a remotely close case. A ruling for the North Carolina lawmakers would flood the federal courts with election litigation that normally plays out in the states, upending the balance of federalism that defines American government. That’s not a conservative result; it’s a dangerously radical one.The Times is committed to publishing a diversity of letters to the editor. 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