 His legal affairs advisors include Martha Minow, Ronald S. Sullivan Jr., Christopher Edley Jr., Eric Holder, and Cassandra Butts.Among his field staff, Paul Tewes and Mitch Stewart led Obama's winning Iowa caucus campaign, and one or the other of them directed field operations in many other crucial states, including Nevada, Minnesota, Texas, Pennsylvania, Ohio, and Indiana.Obama's campaign was notable for extensive use of a logo consisting of the letter O, with the center suggesting a sun rising over fields in the colors of the American flag.