Kenneth Robert Buck (born February 16, 1959) is an American lawyer and politician who has represented Colorado's 4th congressional district in the United States House of Representatives since 2015. From March 30, 2019, to March 27, 2021, Buck served as chair of the Colorado Republican Party, having replaced Jeff Hays. Formerly the District Attorney for Weld County, Colorado, Buck ran unsuccessfully for U.S. Senate in 2010, narrowly losing to Democrat Michael Bennet. In Congress, Buck has emerge...