He was first elected to serve in the House in 1996, serving three terms. He lost his first Senate race in 2002 before a historic win in 2004, when he ousted then-Senate Democratic Leader Tom Daschle.
It took two ballots to decide the race, as Mr. Thune failed to secure a majority on the first ballot of the 53 returning and newly elected Republican senators who will serve in the majority in the next Congress.