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 emerged as one of the foremost proponents of antitrust enforcement in the Republican Party. Early life and education Buck was born in Ossining, New York, in 1959. He and his two brothers were encouraged by their parents, Ruth (Larsen) and James Buck, both New York lawyers, to attend Ivy League colleges. Buck earned a Bachelor of Arts degree in politics from Princeton University in 1981 and completed a 75-page long senior thesis titled "Saudi Arabia: Caught Between a Rock and a Hard Place". Buck later said that the Princeton degree was "more important to [my father] than me". At Princeton, Buck played four years of football on the Princeton Tigers football team, including one year as a defensive back/punter/kicker and three years as a punter, earning All-Ivy League honors as a punter his senior year. After college, he worked in Wyoming at the state legislative services office and received a Juris Doctor from the University of Wyoming College of Law in 1985. He was also an instructor at the University of Denver Law School and for the National Institute for Trial Advocacy in Colorado. Career U.S. Attorney's Office In 1986, Buck was hired by Congressman Dick Cheney to work on the Iran–Contra investigation. Following that assignment, he worked as a prosecutor with the U.S. Department of Justice in Washington D.C. In 1990, Buck joined the United States Attorney's Office for the District of Colorado, where he became Chief of the Criminal Division. Buck was formally reprimanded and required to take ethics classes in 2001 for a meeting he had with defense attorneys about a felony case he thought should not be pursued. Only one of the three men initially indicted on felony charges was convicted, for a misdemeanor offense. Buck said he is "not proud" of the incident that effectively ended his career with the Justice Department, but that he felt it was unethical to prosecute such a "weak" case. One of the three