Christopher Scott Murphy (born August 3, 1973) is an American politician serving as the junior United States Senator from Connecticut since 2013. A member of the Democratic Party, he previously served in the United States House of Representatives, representing Connecticut's 5th congressional district from 2007 to 2013. Before being elected to Congress, Murphy was a member of both chambers of the Connecticut General Assembly, serving two terms each in the Connecticut House of Representatives (1999–2003) and the Connecticut Senate (2003–07). Murphy ran for the U.S. Senate in 2012 after long-time incumbent Joe Lieberman announced in January 2011 that he would retire from politics rather than seeking a fifth term in office. He defeated former Connecticut secretary of state Susan Bysiewicz in the Democratic primary, and subsequently defeated Republican candidate Linda McMahon for the open seat in the general election. Aged 39 at the time, Murphy was the youngest Senator of the 113th Congress. Arkansas' Tom Cotton, elected at age 37, later surpassed Murphy as the youngest incumbent Senator, two years later.