 In November 2002, Dart was the Democratic nominee for state treasurer of Illinois but lost to incumbent Republican Judy Baar Topinka.When Sheahan announced that he would retire as Cook County Sheriff in 2006, Dart announced his candidacy to succeed Sheahan.Dart won the Democratic primary election on March 21, 2006, defeating Sylvester Baker and Richard Remus by a wide margin, and won the general election in November 2006.