John Thune is an American politician serving as the senior United States Senator from South Dakota since 2005. He is a member of the Republican Party and has held various leadership positions, including serving as the Senate Majority Whip from 2015 to 2021. Thune is known for his work on issues such as agriculture, healthcare, and technology. Before his Senate career, Thune served in the U.S. House of Representatives from 2003 to 2005. He was also the South Dakota Republican Party chair and worked in the private sector. Thune is recognized for his commitment to his constituents and his focus on economic growth.