Republican Sen. Susan Collins said Wednesday that Democrat Sara Gideon had called her to concede in their high-profile Senate clash.
It marks a massive blow to Democrats’ hopes of taking over the Senate.
Mrs. Gideon, speaker of the Maine House of Representatives, was one of her party’s prized recruits and led in the polls heading into Election Day.
First elected in 1996, Mrs. Collins has been a staple of Maine politics and is the last Republican senator from New England.
She touted her bipartisan credentials in the hard-fought campaign and was able to thread a political needle in a state that gave electoral votes to both President Trump and Joseph R. Biden.
Democrats hoped Mrs. Collins was vulnerable after backing Supreme Court Justice Brett Kavanaugh.
The race was the most expensive Senate contest in Maine history.
Sen. Todd Young, chairman of the National Republican Senatorial Committee, rejoiced at the news.
“Senator Susan Collins’ dedication to being Maine’s voice would not be silenced by the far-left mobs and special interests who have opposed her independence and commitment to working in a bipartisan manner,” Mr. Young, Indiana Republican, said in a statement. “Mainers recognized what Senator Collins’ life of public service has delivered for Maine.”