The US Supreme Court on Thursday, in a 5-4 decision, allowed the enforcement of an Arizona election law requiring prospective voters to provide “satisfactory evidence of citizenship” upon registering to vote. However, the court kept two lower court blocks on related laws that prevent those with unverified citizenship status from voting in presidential elections or voting early by mail. The justices did not provide any reasoning for their votes.

According to the Supreme Court’s order, Justices Sonia Sotomayor, Elena Kagan, Amy Coney Barrett and Ketanji Brown Jackson would have blocked the citizenship requirement. However, Justices Clarence Thomas, Samuel Alito and Neil Gorsuch would have allowed Arizona to enforce the other provisions at issue.

All provisions before the high court came from a Republican Party-backed 2022 Arizona law, HB 2492, which the US Justice Department sued to partially block months after its passage, arguing that it violated federal voter registration and civil rights law.

After issuing an opinion upholding much of HB 2492 in March, a federal judge in May permanently blocked the provision that required evidence of citizenship to register, A.R.S. § 16-121.01(C), and the provisions that barred voters with unverified citizenship status from voting for president or by mail, A.R.S. § 16-121.01(E) and 16-127(A), among others. The judge, Susan R. Bolton, held that A.R.S. §§ 16-121.01(E) and 16-127(A) were preempted by the federal National Voter Registration Act. Judge Bolton also found that A.R.S. § 16-121.01(C) violated a consent decree reached between the League of United Latin American Citizens of Arizona (LULAC) and the Arizona Secretary of State. The decree stipulated that voters without proof of citizenship could vote in federal elections regardless of whether they used Arizona or federal forms.

Last month, a motions panel of the US Court of Appeals for the Ninth Circuit allowed the evidence of citizenship requirement to go into effect pending an appeal before the court. However, a different three-judge panel from the Ninth Circuit later reversed that decision, holding that the criteria for a stay pending appeal were not met. In a per curium order, the second panel held that the LULAC Consent decree, which allowed voters with unverified citizenship status to vote in federal elections, “remains in force and is binding on the parties,” reversing the stay pending appeal and once again blocking the citizenship requirement. The Supreme Court’s order on Thursday vacated this decision and allowed the provision to go into effect.

The controversy over Arizona’s law comes amid a Republican fear of noncitizens casting ballots and influencing election results even though noncitizens cannot vote in federal elections.

Courts around the US have been dealing with questions that could impact the results of the upcoming 2024 presidential elections. In July, a federal court rejected a Republican challenge to a Mississippi law allowing mail-in ballots to be counted up to five days after election day if they were postmarked on time. Earlier that month, the Wisconsin Supreme Court reinstated the use of drop boxes for absentee ballots.

Arizona will not be permitted to deny those with unverified citizenship status the right to vote in presidential elections or vote early by mail until the Ninth Circuit considers a full appeal of Judge Bolton’s order.