 After her re-election to the Assembly in 2008, Choo stood again for the leadership of the United Democratic Party at the party convention on 6 July 2008.She pushed to broaden and deregionalize the party, and enjoyed broad public support, but ultimately placed second behind Chung Sye-kyun.Choo has served as a member of the Assembly's Foreign Affairs and Unification Committee, and in 2003, she was appointed special envoy to the United States on the North Korean nuclear crisis.