DFL U.S. Sens. Amy Klobuchar and Tina Smith spent much of the fall campaign season leading their Republican opponents and both prevailed in Tuesday's election.

Klobuchar easily won re-election Tuesday night, beating Republican state Rep. Jim Newberger. Smith's race against Republican state Sen. Karin Housley was closer, but ultimately voters chose to return Smith as well.

Klobuchar is a former Hennepin County prosecutor and a potential 2020 presidential contender. In polls, she consistently led Newberger, an emergency medical technician who lives in Becker, by 20 to 30 percentage points.

Smith is the former lieutenant governor who was appointed to the Senate seat by DFL Gov. Mark Dayton in January following the resignation of DFL Sen. Al Franken amid allegations of sexual harassment, putting his seat on the ballot two years ahead of schedule.

While Smith consistently outpaced Housley in the polls, many voters were unfamiliar with both candidates. Republicans and Democrats poured last-minute resources into the contest.

In her victory speech at the DFL gathering in St. Paul, Smith noted the significance of Minnesota electing two female senators. Klobuchar joined Smith on stage.

"I have talked to hundreds of people across the state about why they chose to get involved and dive in this year, and no one put it better than that first-time volunteer I talked to who said ... 'because I feel that it's my responsibility to have a positive impact on the arc of history,'" Smith recounted.

Sen. Amy Klobuchar hugs a supporter before taking the stage after retaining her Senate seat. Evan Frost | MPR News

Smith said she will focus on narrowing the wage gap between men and women, and making health care affordable.

Housley told the crowd at Republicans' election night gathering in Bloomington that she had "hoped to be talking to you under better circumstances tonight, but sometimes God's plans are different than our own. ... We had fun. We had a lot of fun."

Housley congratulated Smith and said it was time to move forward "for the good of the state."

This was the first time in four decades that Minnesotans cast a vote for both of their United States senators in the same election. It's also the first time in state history two women competed for one of Minnesota's seats in the U.S. Senate.

Nationally, Republicans were poised to add to their narrow 51-49 majority in the U.S. Senate.

Democrats played defense in 10 Senate districts around the country that Donald Trump won in 2016. Given Tuesday's results, Smith and Klobuchar will remain in the Senate's political minority next year.