After his defeat, Mondale joined the Minnesota-based law firm Dorsey & Whitney and the National Democratic Institute for International Affairs (1986–93). President Bill Clinton appointed Mondale United States Ambassador to Japan in 1993; he retired in 1996. In 2002, Mondale ran for his old Senate seat, agreeing to be the last-minute replacement for Democratic Senator Paul Wellstone, who died in a plane crash less than two weeks before the election. Mondale narrowly lost the race to Saint Paul mayor Norm Coleman. He then returned to working at Dorsey & Whitney and remained active in the Democratic Party. Mondale later took up a part-time teaching position at the University of Minnesota's Hubert H. Humphrey School of Public Affairs.