A federal judge in Arizona has blocked the enforcement of a state law that required proof of citizenship to vote for the U.S. president. The ruling ensures that Arizonans using a federal voter registration form can cast their ballots in presidential elections. The judge also voided parts of the state law that limited voting only to those providing "satisfactory evidence of citizenship." Additionally, the judge stated that the state does not have the authority to prohibit mail-in voting for individuals using the federal form.