Republican Cindy Hyde-Smith has won a runoff election for a U.S. Senate seat representing the southern state of Mississippi.
Hyde-Smith received 54 percent of the vote Tuesday to defeat Democrat Mike Espy.
She told supporters the win was about "our conservative values," which she pledged to take to Washington.
"And I want everybody to know, no matter who you voted for today, I'm going to always represent every Mississippian," Hyde-Smith said. "I will work very hard, do my very best to make Mississippi very proud of your U.S. Senator."
The election was the final piece of the 2018 Senate midterm elections and sets Republicans up to hold a 53-47 Senate majority when the next session of Congress begins in January, compared to their current 51-49 edge.
Democrats took control of the House of Representatives for the first time in eight years, gaining at least 38 seats in the Nov. 6 voting, with two tight contests still undecided.
Hyde-Smith will finish the final two years of former Sen. Thad Cochran's term after he resigned for health reasons. The seat will be up for election again in 2020.
The run-off election in the deeply conservative, Republican stronghold was held because neither Hyde-Smith, who is white, nor Espy, who is black, won a majority of votes in a four-way race held three weeks ago.
Hyde-Smith was the favorite in Tuesday's election, in part because Mississippi has a long history of electing Republicans and has not elected a black senator for more than a century. But comments she made during the run-off campaign raised doubts about the outcome, prompting President Donald Trump to stage two election-eve rallies in the state to show his support.
He congratulated her on Twitter Tuesday night.
"Congratulations to Senator Cindy Hyde-Smith on your big WIN in the Great State of Mississippi," Trump wrote. "We are all very proud of you!"
Mississippi was one of 11 southern states that seceded from the United States in the 1860s over the rights of white plantation owners to possess slaves, declaring themselves the Confederate States of America. The secession led to the country's deadly Civil War that ended with the South's defeat and surrender in 1865.
But racial disputes endured for decades in Mississippi, with lynchings of black residents and segregation of the races in virtually all aspects of life, including schools, restaurants and other public accommodations, until the 1960s.
Hyde-Smith drew quick scorn when she said that if a political supporter invited her "to a public hanging, I'd be on the front row." She apologized "to anyone offended" by the remark, but photos of her also surfaced of her holding Confederate memorabilia from the Civil War.
In another campaign comment, she suggested "maybe we want to make it just a little more difficult" for liberal college students to vote.
Hyde-Smith contended that Espy had misconstrued her lynching remarks. But the Democrat rebuffed her.
"No one twisted your comments, because your comments were live, it came out of your mouth. I don't know what's in your heart, but we all know what came out of your mouth. It's caused our state harm. It's given our state another black eye that we don't need," he said.
On Monday, state authorities removed two nooses and six hate signs they found on the grounds of the Mississippi State Capitol.
Republicans depicted Espy as out of touch with the state, where he once served as a congressman, and lacking in judgment. He once faced corruption charges — receiving favors while he was the country's agriculture chief in the 1990s — although he was acquitted.