Arizona Republicans are asking the U.S. Supreme Court to review a case that could potentially block 40,000 citizens in the battleground state from voting in the presidential election this November.

The Republican National Committee filed an emergency application for stay earlier in August to reinstate a 2022 Arizona law that would require residents to provide proof of citizenship like a birth certificate or passport to vote in presidential elections and by mail. If reinstated, some Arizonians’ voter registration forms will be rejected this year.

Federal law prohibits noncitizens from voting in elections and there is no proof that it occurs anywhere in the U.S. to a high degree. Republicans asked the court to rule on the issue by Thursday.

Politicians this election year are focusing their efforts on battleground states like Arizona to swing the pendulum in their favor. In 2020, President Joe Biden narrowly won the state by just over 10,000 votes — with Latinos helping to secure his victory.

Analysts said the case, known as the Republican National Committee v. Mi Familia Vota, could “potentially hand Arizona to Donald Trump.” Many of the impacted voters are service members, students and Native Americans who did not have birth certificates on hand when registering to vote, the Los Angeles Times reported.

“Every voter in Arizona has a bedrock right to ensure their votes and their voices are not diluted by ineligible voters casting ballots and impacting our elections and our representation,” Arizona GOP Chairwoman Gina Swoboda said in a release.

Voter advocates said the Republican push in Arizona is another method of disenfranchisement. According to a study by the University of Maryland, nearly 10 percent of voting-age citizens (21.3 million) do not have immediate access to documents that show proof of citizenship. Nearly 4 million people don’t have any legal documents to prove their citizenship. Marginalized groups were more likely to lack documentation, with Republicans least likely.

A study released late last year found that federal-only voters tended to be concentrated on or near college campuses and homeless shelters in Arizona. Young adults were found to be disproportionately impacted by the state’s “unique” voting laws, according to the analysis of the more than 32,000 voters on the list.

The law, if reinstated, would require that Arizona not print presidential candidates on federal-only ballots or configure its voting machines to not count those votes, Republicans said in the court filing.

Arizona has a track record of voter disenfranchisement. In 2004, the state passed a law requiring new voters to show proof of citizenship when registering to vote. This law conflicts with the National Voter Registration Act (NVRA), which mandates that states register people who submitted the standard federal form.

In 2022, Arizona enacted more stipulations for voter registration, including that election officials must reject state forms without citizenship proof and that these voters could not vote for president or by mail.

According to Vox, Arizona has refused to fully register voters who submitted the federal form without providing proof of citizenship, leading to “Federal-Only Voters” who cannot vote in local and state elections but vote in presidential or congressional elections. Less than one percent of those voters are from minority groups — but they could make a difference in the swing state.

Democrats last week announced their own efforts to squeeze out votes in battleground states. The party is targeting about 1.6 million people living abroad who are legally registered to vote in the U.S. They include military personnel, students, people traveling on business and “digital nomads” who work remotely.