House: 1959-1964
Iowa Senate: 2011-2014 Assistant Minority Leader, Iowa Senate: 2011-2014 U.S. Senate: 2015-2027
House: 1937-1940
House: 2019-2025
House: 1971-1982
House: 2013-2017
House: 1969-1970
House: 2019-2023 Senate: 2023-2027 Senate Assistant Minority Leader: 2023-2027
House: 1964-1968, 1981-2000 Senate: 1969-1978
Senate: 1995-2002