Marion Michael Rounds (born October 24, 1954) is an American businessman and politician serving as the junior United States senator from South Dakota since 2015. A member of the Republican Party, he served as the 31st governor of South Dakota from 2003 to 2011.
Rounds was raised in Pierre, South Dakota. He attended South Dakota State University, where he earned his Bachelor of Science degree. He was elected to the South Dakota Senate in 1990, representing the 24th district until 2001. Rounds ran for governor of South Dakota in 2002, and after an upset victory in the Republican primary, won the general election. He was reelected in 2006.
In 2014, Rounds was elected to the United States Senate, succeeding retiring Democrat Tim Johnson. He was reelected in 2020. He has been nominated for reelection in 2026.
Early life, education, and business career
The eldest of 11 children, Rounds was born in Huron, South Dakota, the son of Joyce (née Reinartz) and Don Rounds. He has German, Belgian, Swedish and English ancestry. Rounds has lived in the state capital of Pierre since he was three years old. He was named for an uncle, Marion Rounds, who was killed in the Pacific theater during World War II. Several members of the Rounds family have been involved in state government. His father worked at various times as state director of highway safety, a staffer for the Rural Electrification Administration, and executive director of the South Dakota Petroleum Council. His brother Tim Rounds was a member of the South Dakota House of Representatives, representing District 24, which includes Pierre, from 2003 to 2011 and from 2013 to 2021.
Rounds attended South Dakota State University in Brookings, where he earned his Bachelor of Science in political science.
Rounds is a former partner in Fischer Rounds & Associates, an insurance and real estate firm with offices in Pierre, Rapid City, Mitchell, Watertown and Sioux Falls.
Rounds represented District 24, which was based in Pierre. In 1990, he defeated incumbent state Senator Jacqueline Kelley, 53%–47%. He was reelected in 1992 (60%), 1994 (77%), 1996 (66%), and 1998 (75%). Rounds had to leave the Senate in 2001 because of legislative term limits South Dakota voters had passed in 1992.
Rounds represented Hughes, Lyman, Stanley, and Sully counties. In 1993, he became Senate Minority Whip. In 1995, his peers selected him to be Senate Majority Leader.
As the 2002 race for governor took shape, media and political observers largely dismissed Rounds as an extreme long shot. Until late 2001, then-Congressman John Thune was the front-runner for the nomination. When Thune passed on the race to challenge Senator Tim Johnson, state Attorney General Mark Barnett and former Lieutenant Governor Steve T. Kirby became candidates.
Rounds benefited from the heated competition between Kirby and Barnett, much of which centered on ethical concerns about Kirby's personal business investments and damaged both candidates' reputations, with Barnett's campaign advertisements involving claims "so outlandish that people thought for sure that they were exaggerated or completely fabricated". By staying above the fray, Rounds won the primary by 15 points.
After winning the Republican nomination, Rounds chose State Senator Dennis Daugaard of Dell Rapids as his running mate. Their Democratic opponents were University of South Dakota President Jim Abbott of Vermillion and his running mate, former State Representative Mike Wilson of Rapid City.
Rounds was elected governor on November 5, 2002. The results were as follows:
Republicans: Rounds and Daugaard, 56.8%
Democrats: Abbott and Wilson, 41.9%
Independent: Jim Carlson and Ron Bosch, 0.7%
Libertarians: Nathan Barton and Eric Risty, 0.6%
Two Democratic candidates emerged to challenge Rounds: Jack Billion, a retired surgeon and former state legislator from Sioux Falls, and Dennis Wiese, the former president of the South Dakota Farmers Union. Billion easily won the nomination and selected Rapid City school board member Eric Abrahamson as his running mate.