(The Center Square) – The U.S. Supreme Court determined that voters must provide proof of citizenship when registering to vote through a state voter registration form – an emergency order requested by Arizona Senate President Warren Petersen.

Arizona was joined by 23 other states in filing a brief in support of the Arizona law that requires proof of citizenship in order to vote.

“On August 1, a three-judge panel vacated an emergency stay decision issued unanimously by another Ninth Circuit panel on July 18,” reads a press release from the Arizona State Senate. “For more than two weeks, the ruling effectively allowed any individual in Arizona to use a state form to register to vote, without providing proof of citizenship, in order to cast a ballot in federal races like U.S. President and Congress. Shockingly, federal law does not currently require citizenship documentation to vote in federal elections.”

The ruling still allows Arizonans without identification to register to vote as "federal only" voters, a federal mandate that includes an attestation of citizenship. The change doesn't affect those already registered. A state voter registration submitted without ID will be rejected.

The legal battle comes from opposition against a law passed in 2022 that would restrict voters who didn’t present proof of citizenship when registering to vote in state elections.

“Without Congress taking action to implement federal laws safeguarding against non-U.S. citizens from casting a ballot, the security of our democratic process for legal U.S. citizens is in grave danger as the potential remains for millions of individuals who've entered the United States illegally under the Biden-Harris Administration to influence the outcome of our elections,” reads the news release

Included in the 24-state coalition are the attorney generals of Alabama, Alaska, Florida, Georgia, Iowa, Indiana, Kansas, Kentucky, Louisiana, Missouri, Montana, Nebraska, New Hampshire, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Texas, Utah, Virginia and West Virginia.

Arizona Attorney General Mayes is not a member of the coalition.

Arizona Secretary of State Adrian Fontes has expressed concerns leading up to this decision, saying that around 40,000 voters in Arizona would be disqualified from voting due to using a federal voter registration form.

"My concern is that changes to the process should not occur this close to an election, it creates confusion for voters,” Fontes said in a statement on Thursday. "We respect the Court's decision and will implement these changes while continuing to protect voter access and make voting a simple process."

However, he did state that voters who did not include proof of citizenship on their voter registration form can register to vote using the National Mail Voter Registration Form, which requires an “attestation of citizenship under penalty of perjury,” according to the press release.

This form can be found at azsos.gov/media/91.

However, Petersen said that this is still not enough and that voters should have to provide proof of citizenship, not just attest that they are on a form.

"Our legal battle is far from over," Petersen said in a statement on Tuesday. "While we're grateful SCOTUS recognized our state's sovereignty by allowing our laws requiring proof of citizenship to register to vote in Arizona be enforced, individuals who are living here illegally are still able to register on a federal form without providing proof of citizenship. They must only attest they are lawful citizens, then they are able to vote in the presidential and congressional races, as well as by mail, thus influencing the outcome of our elections. We will continue litigating this issue in the coming months with a goal of ensuring only legal U.S. citizens are casting a ballot."