Charles Ernest Grassley (born September 17, 1933) is an American politician serving as the president pro tempore of the United States Senate, and the senior United States senator from Iowa. He is currently in his seventh term in the Senate, having first been elected in 1980.
A member of the Republican Party, Grassley previously served eight terms in the Iowa House of Representatives (1959–1975) and three terms in the United States House of Representatives (1975–1981). He has served three stints as Senate Finance Committee chairman during periods of Republican Senate majority. When Orrin Hatch’s Senate term ended on January 3, 2019, Grassley became the most senior Republican in the Senate. He was appointed president pro tempore of the Senate for the 116th United States Congress, making him third in the presidential line of succession after the vice president and speaker of the House.