On June 30, the Supreme Court agreed to hear a case called Moore v. Harper. With all the controversial decisions handed down by the Court this term, its decision to take up this case slid under most radar detectors. But it could be the most dangerous case on the Court’s upcoming docket. You need to know about it.

Here’s the background: Last February, the North Carolina Supreme Court blocked the state’s Republican controlled general assembly from instituting a newly drawn congressional district map, holding that the map violated the state constitutional ban on partisan gerrymandering. The Republican Speaker of the North Carolina House appealed the decision to the U.S. Supreme Court, advancing what’s called the “independent state legislature” theory. It’s a theory that’s been circulating for years in right-wing circles. It holds that the U.S. Constitution gives state legislatures alone the power to regulate federal elections in their states.

We’ve already had a preview of what this theory could mean. It underpins a major legal strategy in Trump’s attempted coup: the argument that state legislatures can substitute their own judgment of who should be president in place of the person chosen by a majority of voters. This was the core of the so-called “Eastman memo” that Trump relied on (and continues to rely on) in seeking to decertify Biden’s election.

The U.S. Constitution does grant state legislatures the authority to prescribe “the Times, Places and Manner of holding Elections.” But it does not give state legislatures total power over our democracy. In fact, for the last century, the Supreme Court has repeatedly rejected the independent state legislature theory.

Yet if we know anything about the conservative majority now controlling the Supreme Court, it’s that they will rule on just about anything that suits the far-right’s agenda.

Conservatives on the Court have already paved the way for this bonkers idea. Then-Chief Justice William Rehnquist was an early proponent. In his concurring opinion in Bush v. Gore, the 2000 case that halted the recount in Florida in the presidential election, Rehnquist (in an opinion joined by Justices Antonin Scalia and Clarence Thomas) asserted that because the state court’s recount conflicted with deadlines set by the state legislature for the election, the court’s recount could not stand.

The issue returned to the Supreme Court in 2020, when the justices turned down a request by Pennsylvania Republicans to fast-track their challenge to a Pennsylvania Supreme Court ruling that required state election officials to count mail-in ballots received within three days of Election Day. In an opinion that accompanied the court’s order, Justice Alito (joined by Justices Clarence Thomas and Neil Gorsuch) suggested that the state supreme court’s decision to extend the deadline for counting ballots likely violated the U.S. Constitution because it intruded on the state legislature’s decision making.

Make no mistake. The independent state legislature theory would make it easier for state legislatures to pull all sorts of additional election chicanery, without any oversight from state courts: ever more voter suppression laws, gerrymandered maps, and laws eliminating the power of election commissions and secretaries of state to protect elections.

If the Supreme Court adopts the independent state legislature theory, it wouldn’t just be throwing out a century of its own precedent. It would be rejecting the lessons that inspired the Framers to write the Constitution in the first place: that it’s dangerous to give state legislatures unchecked power, as they had under the Articles of Confederation.

The Republican Party and the conservative majority on the Supreme Court call themselves “originalists” who find the meaning of the Constitution in the intent of the Farmers. But they really don’t give a damn what the Framers thought. They care only about imposing their own retrograde and anti-democracy ideology on the United States.

But we can fight back.

First, Congress must expand the Supreme Court to add balance to a branch of government that has been stolen by radicalized Republicans. This is not a far-fetched idea. The Constitution doesn’t specify how many justices there should be – and we’ve already changed the size of the Court seven times in American history.

Second, Congress must impose term limits on Supreme Court justices, and have them rotate with judges on the U.S. courts of appeals.

Third, Congress must restore federal voting rights protections and expand access to the ballot box. We need national minimum standards for voting in our democracy.

Obviously, these reforms can happen only if Democrats retain control of the House in the midterm elections and add at least two more Democratic senators—willing to reform or abolish the filibuster.

So your vote is critical, and not just in federal elections. Make sure you also vote for state legislators who understand what’s at stake to preserve our democracy. Because, as this Supreme Court shows, the future of our democracy is not guaranteed.