A divided Supreme Court ruled Thursday that Arizona could require proof of citizenship when registering new voters for future elections.
But the court rejected a request by the Republican Party to block voting in November by more than 40,000 people who had already registered without providing such proof.
The court did not explain its decision, which arose from an emergency appeal filed by the Republican National Committee.
Conservative justices Clarence Thomas, Samuel A. Alito Jr. and Neil M. Gorsuch said they would have granted the appeal in its entirety.
Justices Elena Kagan, Sonia Sotomayor, Amy Coney Barrett and Ketanji Brown Jackson have reportedly denied it outright.
Judges generally disapprove of lawsuits or appeals seeking to change voting rules on the eve of an election.
In this case, Arizona Republican leaders were seeking to enforce a new law that would prohibit Arizonans from voting if they do not show a birth certificate or passport when registering.
A federal judge in Phoenix had blocked the 2022 law from going into effect because it conflicted with the federal “motor voter” law.
and a 2013 Supreme Court ruling that upheld the law in an Arizona case.
At the time, in a 7-2 decision, Justice Antonin Scalia said federal law required Arizona and other states to “accept and use” the standard federal form for registering new voters even if it did not include proof of citizenship.
In dissent then were Thomas and Alito.
Following that ruling, Arizona adopted a two-track system for voter registration. Residents registering to vote in state and local elections were required to prove their citizenship.
Those who registered through the federal form signed an affidavit declaring that they were U.S. citizens. These “federal-only voters” were allowed to cast ballots only for members of Congress and the president.
The state subsequently agreed in a 2018 consent decree to grant full registration to new voters whose residency and citizenship could be confirmed through its motor vehicle department's database.
But two years ago, the Republican-controlled Legislature passed a new law to prohibit registered voters who did not provide proof of citizenship from casting ballots in a presidential election.
The Justice Department and voting rights advocates filed a lawsuit challenging the law. Last year, U.S. District Judge Susan Bolton held a 10-day trial in Phoenix and blocked enforcement of the new proof-of-citizenship requirement.
The 9th Circuit Court of Appeals, by a vote of 2 to 1, refused to lift his order.
The RNC, the Arizona Senate and the speaker of the state assembly filed an emergency appeal with the Supreme Court on Aug. 8. They argued that the Arizona Legislature has the final authority to decide who can vote in the state's elections.
But Arizona's attorney general and secretary of state, both Democrats, urged the court to reject the appeal.
Secretary of State Adrian Fontes told the court that a ruling altering current registration rules “would create chaos and confusion.” He said newly registered voters who used the federal form would be disenfranchised, along with “the 42,301 voters registered at the federal level alone” who will not be able to vote in the presidential election.
