A federal appeals court in Denver is scheduled to hear arguments Aug. 25 in a dispute over whether Kansas and Arizona can require voters using a federal registration form to show proof of citizenship.

It's the first of several significant cases this fall that could determine who gets to vote, and how, in at least six states. The outcomes could also answer a much broader question: Who gets to decide?

A national voter registration form was created in the 1990s to make registering to vote easier. The form is short and simple, and can be used to register to vote in just about every state. It asks for an individual's name, address and age and also requires individuals to affirm that they are citizens of the U.S. It doesn't ask for any proof.

But both Kansas and Arizona passed laws requiring individuals to show a birth certificate or some other proof of citizenship when they register to vote. So they asked the federal government to adjust the national form to reflect this. The federal government refused, so the two states sued.

"Under Article One, Section Two of the U.S. Constitution, the states solely get to decide who votes in elections and get to police those qualifications," argues Kansas Secretary of State Kris Kobach. He says the Supreme Court recognized that in a related case last year and all but invited the states to sue.

"It's become a growing problem for aliens to become registered," says Kobach. "And in many of those cases, they go on to vote. And every time an alien votes, it effectively cancels out the vote of a U.S. citizen."

But Wendy Weiser of the Brennan Center for Justice in New York thinks the problem of noncitizens voting is extremely small, especially compared with the impact proof-of-citizenship laws can have on legitimate voters who don't own a birth certificate or other required document.

"If Kansas and Arizona win, it will be much harder for many people to register," says Weiser.

Her group, representing the League of Women Voters, along with the U.S. Election Assistance Commission, has asked the federal appeals court to overturn an earlier ruling that the federal government should adjust its registration form as Kansas and Arizona have requested.

Weiser says if that ruling is allowed to stand, it could open the floodgates for other states to make similar demands, and undercut the whole purpose of having a simple federal form.

"Congress tried to set uniform standards for voter registration," she says. "And the states here are trying to undermine that, saying they should be able to impose their own requirements on the federal voter registration form."

Her concerns are not unfounded. Numerous states have recently imposed new voting restrictions, many of which are also being challenged in the courts this fall.

"We see cases in North Carolina, in Ohio, in Wisconsin, among other states, that, you know, have the potential both to affect the voting process, but also to create important rules and principles," says Edward Foley, an election law expert with the Moritz College of Law at Ohio State University.

As Foley notes, there's a lot going on. Cutbacks in early voting are being challenged in Ohio. In North Carolina, the NAACP has said it will appeal a recent decision allowing sweeping voting changes to go into effect this November. Wisconsin is defending its new photo ID requirement in federal court Sept. 12. And voting rights groups will be in court Sept. 2 to challenge a Texas voter ID law.

Foley says it's all part of the shake-out from a Supreme Court ruling last year that overturned a crucial section of the federal Voting Rights Act, Section Five. Now, voting rights advocates are trying to use a different part of the law, Section Two, to block voting restrictions.

"There is sort of a new wave of litigation involving Section Two of the Voting Rights Act and whether or not voting rules of any kind have racially discriminatory impact," says Foley.

Advocates like Weiser argue that many of the new state laws disproportionately hurt minority voters, something that people like Secretary of State Kobach strongly dispute.

How all this plays out, says Foley, will affect not only what voters in a few states face in November, but what all voters face in the years to come.

Copyright 2021 NPR. To see more, visit https://www.npr.org.