Mike Rounds
Mike Rounds, a Republican former governor of South Dakota, defeated Democrat Rick Weiland and independent Larry Pressler to win the race for the state's U.S. Senate seat. Getty Images

Former Republican Gov. Mike Rounds of South Dakota defeated Democratic challenger Rick Weiland and independent candidate Larry Pressler in Tuesday’s election for the state’s open U.S. Senate seat. Rounds will replace incumbent Sen. Tim Johnson, D-S.D., who announced in March 2013 he would retire at the end of his term.

Various polls predicted a Rounds victory in the weeks ahead of the 2014 midterm elections. A Rasmussen poll published Oct. 29 projected Rounds would receive 45 percent of the vote, compared to 32 percent for Weiland and 20 percent for Pressler. A joint NBC News/Marist College poll predicted a similar outcome, with 43 percent for Rounds compared to 29 percent for Weiland and 16 percent for Pressler. A second independent candidate, Gordon Howie, was routinely dismissed as a distant fourth.

By Tuesday, the New York Times, the Washington Post’s Election Lab and Nate Silver’s Five Thirty Eight blog all gave Rounds a greater than 99 percent chance of winning South Dakota’s U.S. Senate race. FiveThirtyEight.com predicted a 12 percent margin of victory.

Johnson’s impending retirement after nearly two decades in office provided the GOP with a chance to seize the popular Democratic senator’s seat. Rounds quickly emerged as the favorite. However, public scrutiny over the EB-5 visa campaign he ran while South Dakota’s governor allowed Weiland, a businessman and former South Dakota state director for the AARP, and Pressler, who served three terms in the Senate as a Republican, to close the gap in October, the Associated Press notes.

But Rounds maintained his lead ahead of Tuesday’s election amid infighting between Weiland and the Democratic Senatorial Campaign Committee. Weiland bashed the DSCC over the content of the negative ads it aimed at Rounds and accused the organization of supporting Pressler. Rounds’ campaign has portrayed Pressler as an ally of President Obama and a recent Sioux Falls Argus Leader poll found twice as many Democrats as Republicans supported Pressler.

Pressler lost his Senate seat in 1997 to Johnson and served in the private sector before his entry in the South Dakota’s 2014 U.S. Senate race. Vowing to facilitate compromise across the aisle and battle corruption in Washington, Pressler enjoyed some early success but remained third in polls ahead of Election Day.

Rounds raised about $4.5 million for his campaign, compared to about $2 million for Weiland. Pressler struggled to raise funds and reported just $166,276 in cash on hand as of Oct. 19.

Rounds served as governor of South Dakota from 2003 to 2011. Prior to that, he spent a decade in the South Dakota Senate.