South Dakota is a Republican, red state, where conservatives have for decades controlled the governorship and the legislature. But the voters have regularly used citizen-initiated referendums and constitutional amendments to advance progressive proposals: increasing the minimum wage, legalizing marijuana, defending abortion rights, and cracking down on corporate influence.

This is not an unheard-of phenomenon in states where Republicans control the governing apparatus. In 2020, when Florida backed Republican Donald Trump in the presidential election, the electorate voted to hike the minimum age to $15 an hour; and in 2018, when Republican Ron DeSantis narrowly won the state’s gubernatorial race, voters also endorsed a sweeping proposal to restore voting rights to formerly incarcerated people.

Republicans used to accept these setbacks as a democratic reality that they just had to live with.

But no more.

An increasingly authoritarian Republican Party and its allies in the corporate community have launched aggressive efforts to undermine direct democracy. This is happening in states across the country that allow citizen-initiated referendums of major issues. But the fight in South Dakota has been especially intense in recent years.

South Dakota Republicans have used legislative maneuvers and the courts to try and upend voter-driven measures. And this year, they went even further, with a scheme to rewrite the rules: A proposed constitutional amendment—placed on the June 7 statewide ballot by the GOP-dominated legislature, and backed by Republican Governor Kristi Noem, a 2024 presidential prospect—would have dramatically increased the popular-vote threshold from a simple majority to 60 percent.

In essence, South Dakota Republicans wanted to impose a variation on the US Senate’s filibuster rule, which would have allowed just 40 percent of the state’s voters to block broadly popular measures. Why? Because a proposal that has qualified for the November ballot in South Dakota seeks to expand access to Medicaid for low-income families. After the Affordable Care Act passed in 2010, states across the country embraced Medicaid expansion, but conservative governors and legislators, including the Republicans in South Dakota, have continued to block the move as part of their broader opposition to “Obamacare.”

Political analysts expect that a majority of South Dakotan voters will support expansion in November. Thus, the GOP’s intervention to require a supermajority.

Unfortunately for the Republicans, the voters rejected the antidemocratic strategy by a 2-1 margin on Tuesday. “South Dakotans came out because they knew the sacred tradition of majority rule was on the ballot,” said Zach Nistler, the campaign spokesperson for South Dakotans for Fair Elections, which opposed the amendment.

The overwhelming rejection was not just a setback for South Dakota Republicans. It was also a blow against the national conservatives who supported the supermajority amendment, especially the group Americans for Prosperity, a longtime political vehicle for the right-wing Koch network. South Dakota, a tax haven for the superrich, has long drawn the interest of out-of-state billionaires and the political organizations they fund. So it was no surprise that Americans for Prosperity, a pet project of Kansas-based billionaire Charles Koch, poured more than $835,000 into the campaign to win approval of the amendment—a substantial sum in a state with a population of just 879,336.

But opponents, including the South Dakota Farmers Union, the South Dakota Education Association, the South Dakota State Medical Association, the American Cancer Society Cancer Action Network, and the South Dakota Democratic Party, forged a statewide coalition that warned, in the words of the veteran progressive Rick Weiland and the group Dakotans for Health, “Democracy is under assault in the Rushmore State.”

On Tuesday, democracy won. Big.

At a point when there are so many threats to voting rights and fair elections, the South Dakota result provided a boost for democracy advocates nationwide. But the fight is not over. The Fairness Project, which supported the activists who opposed the amendment, celebrated the fact that, as the group’s executive director, Kelly Hall, said, “the people of South Dakota have preserved their right to use direct democracy.” But the group stresses that the South Dakota battle should be seen as part of an “orchestrated and ongoing attacks on our democratic institutions.”

The bad news is that the fight is ongoing, in South Dakota and nationally. The good news is that the defenders of democracy have proven they can prevail, even in a very red state.