The groups trying to undo the state’s purge of tens of thousands of Ohioans from voter rolls because of failing to vote or confirm home addresses have a powerful new ally in their court fight — the U.S. Justice Department. The legal battle erupted in April when the Ohio A. Philip Randolph Institute and the Northeast Ohio Coalition for the Homeless filed suit in federal court in Columbus. It challenged Ohio Secretary of State Jon Husted’s move to revoke the registrations of an unspecified number of residents because they didn’t respond to address verification requests or hadn’t voted in four years. U.S. District Judge George Smith upheld Husted’s actions on June 29. The plaintiffs, who are represented by the American Civil Liberties Union of Ohio and the public policy group Demos, appealed to the Sixth U.S. Circuit Court of Appeals in Cincinnati.