Gary Warren Hart (born Gary Warren Hartpence, November 28, 1936) is an American diplomat, politician, lawyer, author, professor and commentator. He served as a U.S. Senator representing Colorado (1975–1987), and sought the Democratic nomination for President in 1984 and 1988. Hart was appointed to be the United States Special Envoy for Northern Ireland in October 2014. He and his wife, Lee, live in Kittredge, Colorado, where they own a ranch named Troublesome Gulch.