South Dakota's Mike Rounds defeats challenger Dan Ahlers in race for US Senate seat

• Sen. Mike Rounds faced off against Democratic challenger Dan Ahlers.
• Shortly after polls closed at 8 p.m. local time/9 p.m. ET, DDHQ and Insider called the race in Rounds' favor.
• Rounds gained his Senate seat in 2014 after defeating his Democratic opponent by 21 percentage points.
• South Dakota overwhelmingly voted for President Donald Trump over Hillary Clinton in the 2016 presidential election, so Rounds' victory was expected.
• See the live coverage and full results from the U.S. Senate elections.

South Dakota Sen. Mike Rounds successfully defended his US Senate seat against challenger Dan Ahlers, who is a Democratic state lawmaker. Shortly after polls closed at 8 p.m. local time/9 p.m. ET, DDHQ and Insider projected the incumbent would hold the deeply red state.

Rounds was elected to Congress in 2014 when he defeated Democrat Rick Weiland by 20.9 percentage points. He previously served as the governor of South Dakota from 2003 to 2012.

In the 2016 presidential election, South Dakota overwhelmingly voted for Donald Trump over Hillary Clinton by just under 30 points.

Before Election Day, the contest was "safe" Republican, per projections by Sabato's Crystal Ball with the University of Virginia Center for Politics.