With Election Day approaching, an odd little story from Dodge City, Kansas, made headlines in The New York Times and The Washington Post last week. Local elections officials in the Wild West outpost of yore, now a meatpacking center that’s majority-Latino, had moved their lone voting place outside the city limits, more than a mile from the nearest bus stop, as anti-immigration crusader Kris Kobach—the state elections chief—was fighting off a strong Democratic challenge in his quest for the governorship.

The whole controversy seemed so obviously outlandish—the kind of over-the-top effort to deter voters of color that could only happen in the Deep South or Kobach’s Kansas—that it’s no wonder the story was catnip for national reporters. While another secretary of state overseeing his own election for governor, Kobach’s Georgia ally Brian Kemp, had been garnering scrutiny for months with his massive “purges” of registered black voters, and while reports on the perils of voter ID laws have become numbingly familiar, the Dodge City tale offered a colorful twist on the theme of race-based voter suppression. The Times editors couldn’t resist a cheeky headline for this saga: “To Cast Their Ballots, These Voters Will Have to Get Out of Dodge.”

But the only unusual thing about this story was that it made news at all. Over the past decade, Republican elections officials have been shuttering polling places in minority neighborhoods, low-income districts, and on college campuses at a feverish pace. When Barack Obama was elected president in 2008, the U.S. had more than 132,000 polling places; by the time Donald Trump ascended to the White House, eight years later, more than 15,000 of them had been closed nationwide. After 2013, when the U.S. Supreme Court basically lifted federal Voting Rights Act oversight from states that were particularly notorious for racial discrimination in elections—including Arizona, Georgia, Indiana, and Texas—the pace of poll closures went into hyperdrive. Thanks to Shelby County v. Holder, if you ran elections in a majority-black county in Georgia, or a booming Latino neighborhood in Houston, you no longer had to ask the Department of Justice to approve a change in where people could vote, or to prove the intent wasn’t discriminatory.

While voter ID laws must be passed by lawmakers, guaranteeing news coverage and public debate, it’s a snap to move or close polling locations. In most states, it can be done unilaterally—all that’s required is a local elections board or official with an eye toward giving Republicans an artificial advantage to seize their chance, and then provide some form of public notice. Closing polls or moving them to white neighborhoods (or all the way out of town) is thus the quietest and least visible form of voter suppression. And studies show that it can be startlingly effective in reducing voting rates—largely at the expense of Democrats. In 2018, this insidious form of targeting poor, black, Latino, and young voters could be the hidden factor in delivering a passel of key elections for Congress and governorships to the GOP—just as it boosted Donald Trump’s presidential bid in 2016.

Stick a pin on any map of marquee midterm races this year, and you’ll find poll closures targeting Democratic voters. A lot of them. Texas, where Ted Cruz is struggling to fend off Beto O’Rourke’s Senate challenge—and where Republicans have long feared the rising tide of young Latinos—has closed more than 400 polling places since 2013, leading the nation in that dubious statistic. Arizona, where Latinos are also threatening the GOP’s hegemony and Democrat Krysten Sinema is neck-and-neck against Rep. Martha McSally for Jeff Flake’s abandoned Senate seat, has closed 200, outpacing Texas on a per capita basis.