Many will remember the infamously confusing Palm Beach County butterfly ballot , which led to 26,000 misvotes, a recount, and ultimately handed George W. Bush the presidency in 2000. Twenty years later, we have new ballot design problems to deal with—and there’s one you’ve probably never heard of.

Most of the ballot design flaws detailed in a recent resource from the Brennan Center for Justice seem rather innocuous. But there’s one in that, if fixed, could reduce margin of error and thereby make the voting system overall more reflective of voters’ intent: ballot design that splits one contest into two columns on a bubble-style page.

There are a few other permutations of this layout, and they all share one key flaw: They split up information that should be categorized together. The first contest on a ballot might fall below the ballot instructions in the first column, causing voters to miss it. A contest might be split into two columns because there’s a large number of candidates to consider—or, on an electronic voting system, there might be two contests on the same page.

These layouts violate the “one idea, one page” guideline that the Center for Civic Design, an organization that advocates for better electoral UX design, issued in its “Field Guides to Ensuring Voter Intent,” says the Center’s director, Whitney Quesenbery. The overarching problem? They break user expectations.

Of course, in any election, there’s plenty that can go wrong: the spread of misinformation, purging of voter rolls, voter suppression, foreign interference, and more. But the split-contest flaw—and poorly designed ballots more generally—are one of the most frustrating problems because they’re relatively easy to fix. In the United States, with all the problems around election safety and hacking, elections don’t have room for human error caused by poor design.

A precedent of inconsistency

Design flaws that split up contest information have played out to dramatic effect in a few key counties: Broward County, Florida, in 2018, and Sarasota, Florida, in 2006. In Broward County, the ballot had a block of lengthy instructions in three languages that ran down the first column. The ballot itself was really long—around 21 inches—so it probably didn’t fit on the table, suggests Quesenbery. After reading the instructions in English, many voters skipped ahead to what was seemingly the first race—the governor’s race at the top of the second column. But what they didn’t realize is they skipped the Senate and House of Representatives contests, which were hidden at the end of the instructions.

As a result, 3.5% fewer votes were cast for the senate race as compared to the governor race. “I know it sounds crazy, but as people mark down the ballot, they don’t look to the left or right, they look down the column they’re voting in, and a large number of them just never looked to the left to see that there were two spaces there,” Quesenbery says. To meet voter expectations, the first contest shouldn’t have shared real estate with voter instructions in the first column. It should’ve started at the top of the second column, where the eye goes first.