Missouri is one of several states to bring up tighter voting-related laws over the last few years. The bill under consideration is one of the stricter laws to come up since North Carolina passed a passel of rules to tighten voting regulations in 2013, including shortening early voting, eliminating same-day registration, and a photo-ID requirement. That law, in turn, has been described as the nation’s strictest since the Supreme Court’s 2013 decision in Shelby County v. Holder eliminated a requirement that jurisdictions with a history of discrimination pre-clear new voting laws with the Department of Justice, which had effectively blocked most stricter laws. The North Carolina law is subject to a court challenge. A federal judge on Monday ruled against plaintiffs challenging the law, but the decision has already been appealed, and the Fourth Circuit said Thursday it would expedite the case. Many experts expect the Supreme Court to have the final say.

The arguments in Missouri are familiar from North Carolina and elsewhere: Republicans argue that voter-ID laws are essential to preserve the sanctity of elections, lest fraudulent votes be cast. Besides, they say, state-issued photo ID is required for a range of normal activities, like driving a car. Is it really so much to ask people to produce one before they vote?

Democrats and other advocates respond that such laws are simply tools of voter suppression. They point out that there are next to no documented cases of voter fraud, and describe bills like this as a solution in search of a problem. They also note that driving a car, unlike voting, is not a fundamental right, and point to the fact that studies have shown that such laws are most likely to affect poor, young, and minority voters. (For example, Missouri’s changes would exclude photo ID from state universities.) It’s no coincidence, they say, that those are blocs that overwhelmingly vote Democratic.

In some states, Republican lawmakers have slipped up and said just that. “Now we have photo ID, and I think photo ID is going to make a little bit of a difference as well,” U.S. Representative Glenn Grothman of Wisconsin said earlier this month. In 2012, the Republican leader of the Pennsylvania state house said voter ID was “gonna allow Governor Romney to win the state of Pennsylvania.” (Instead, a judge blocked the law and Obama won the state.)

“Missouri is one of those swing-ish states where you’ve got Republican control and the thinking is that this could make a difference, like North Carolina,” said Rick Hasen, a professor of law of the University of California, Irvine, and election-law expert. Barack Obama narrowly lost the state in 2008, and while it might not be on the map in 2016, there is a Senate race, too.

Missouri voters already have to show some form of ID to vote, but the requirement is liberal—accepted documents include an expired license, an out-of-state license, a student ID, utility bills, paychecks, and more.