By the time Senator Harkin finishes his fifth term, he will have represented the people of Iowa in the United States Congress for an incredible 40 years. He has served in the U.S. Senate longer than any Democrat in Iowa's history. During his tenure, he has fought passionately to improve quality of life for Americans with disabilities and their families, to reform our education system, and ensure that every American has access to affordable health care. Senator Harkin will be missed, and Michelle and I join Iowans in thanking him for his longstanding service and wish him and his wife Ruth all the best in the future.
Barack Obama, Statement on Senator Thomas R. Harkin's Decision Not To Seek Reelection Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/303505