Walter Mondale was a liberal Democrat, active in the Minnesota Democratic-Farmer-Labor Party. He served as state attorney general from 1960-1964. When Hubert Humphrey became vice president in 1964, Mondale was appointed to replace him in the U.S. Senate, where he served until 1977. In 1976, Jimmy Carter chose Mondale to be his vice president. In 1984, Mondale became the first major-party candidate to choose a female running mate, Geraldine Ferraro. After the Mondale-Ferraro ticket lost to the incumbent Ronald Reagan, Mondale continued to be involved in politics, serving as U.S. ambassador to Japan from 1993 to 1996. He stepped in for Paul Wellstone, when Senator Wellstone died in a plane crash while running for his third term in 2002, but Mondale lost the Senate race to Norm Coleman.