A US federal judge, Sparkle Sooknanan, ruled on Friday that the Justice Department unlawfully obtained state voter rolls to check them against a federal immigration database (SAVE, a system used to verify citizenship and immigration status) and flag voters it deemed ineligible. She found the policy understated the risk of wrongly removing eligible citizens, including naturalised ones with outdated records, and said Congress left the power to decide who votes with the states. The ruling is a setback for President Donald Trump's push for greater federal oversight of elections ahead of the November 3 midterms, though its practical effect may be limited by a federal ban on systematic voter roll purges in the 90 days before an election; the Justice Department said it was reviewing the decision.