SIOUX FALLS, S.D. — Republican U.S. Sen. John Thune and Democratic candidate Jay Williams sparred Thursday over the character of their parties’ presidential nominees at the first debate in their Senate race.

Thune said both Democrat Hillary Clinton and Republican Donald Trump are flawed presidential candidates. He wants Trump to exit the race in favor of GOP vice presidential nominee Mike Pence, but has said he’s not voting for Clinton. He added that he believes Clinton’s policies would be harmful for South Dakota.

Williams called Trump a “sexual predator,” criticizing him over the recent release of a 2005 tape that captured Trump talking about kissing and grabbing women. Clinton is a role model who has worked for women and children her entire career, Williams said during the forum on South Dakota Public Broadcasting.

In the Senate contest, Thune cast himself as a leader who is making headway for South Dakota despite partisan gridlock in Washington. He touted accomplishments including his push for the 2015 expansion of an enormous bomber training area over the Northern Plains and a law that overhauled the federal agency that serves as economic watchdog of the country’s freight rail network.

“People want results,” Thune said. “The work that I’m doing in the United States Senate, we’re getting results, we’re getting things done.”

Thune repeatedly hit Williams for supporting tax increases, calling him perhaps the most liberal Democrat he’s met in South Dakota. Williams said he’s “nonpolitical” and can go to Washington to reach across the aisle, labeling Thune an obstructionist who hasn’t worked well with President Barack Obama.

“I bring you the opportunity to vote for somebody who is just like you, a regular South Dakotan, not a politician, not beholden to a party and not beholden to special interest and big money groups,” said Williams, a Yankton businessman running a longshot campaign while Thune seeks a third term in office.

Williams advocated for working to address climate change and for investing in public works programs, including building an electric grid that could distribute wind energy from South Dakota.

Williams’ low-budget campaign has focused on social media as key way to reach voters. Meanwhile, Thune has a staggering reported cash advantage in the race, with nearly $12.5 million compared to Williams’ roughly $24,000.

The third-ranking Senate Republican, Thune narrowly defeated Democratic leader Tom Daschle in 2004 to take the seat.