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SIOUX FALLS, S.D.-- South Dakota Republican John Thune easily retained his U.S. Senate seat Tuesday in a rare unopposed race.

Senate historians say Thune is just the third Republican to run unopposed for the body since direct elections were established in 1913.

The outcome had been close the other two times Thune ran for Senate.

Thune, 49, captured the national spotlight in 2004 when he defeated Democrat and then-Senate Minority Leader Tom Daschle by a mere 524 votes. Two years earlier, he barely lost to Sen. Tim Johnson, who holds South Dakota's other seat in the chamber.

He has since ascended in the Republican party ranks and is considering a run for president in 2012. A decision on whether he'll pursue the White House will come sometime next year, he has said.

Thune, now of Sioux Falls, grew up in the small town of where former Sen. Jim Abdnor saw him play high school basketball in the 1970s. Thune went to work for Abdnor in 1984, and he credits Abdnor for getting him started in politics.

After Abdnor lost his Senate seat to Daschle in 1986, Thune followed Abdnor when he was appointed head of the Small Business Administration.

Thune returned to South Dakota in 1989 to become executive director of the South Dakota Republican Party. He decided to run for South Dakota's lone seat in the U.S. House in 1996 when Tim Johnson gave up the spot to run for the Senate. Thune was considered an underdog to fellow Republican Lt. Gov. Carole Hillard, who was better known and had more money, but he won the primary and the general election.

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Thune won re-election in 1998 and 2000, but pledged to serve no more than six years in the House.

He challenged Johnson for his Senate seat in 2002.