In March 2003, Huntsman resigned his post in the Bush administration. In mid-August, three-term incumbent Governor Mike Leavitt, whom Huntsman strongly supported, decided not to run for re-election in order to become Administrator of the Environmental Protection Agency in the Bush Administration. Shortly thereafter, Huntsman filed papers to run for Governor of Utah. In the June 2004 Republican primary, Huntsman defeated State Representative Nolan Karras 66–34%. In November 2004, Huntsman was elected with 58% of the vote, defeating Democratic Party nominee Scott Matheson Jr. In 2008, Huntsman won re-election with 77.7% of the vote, defeating Democratic nominee Bob Springmeyer.