U.S. Sen. Raphael Warnock fended off a challenge from Republican Herschel Walker to win a full six-year term that broadens the Democratic majority in the chamber after a turbulent runoff campaign that sharpened partisan divides in one of the nation’s most politically competitive states.

Warnock’s victory Tuesday was a rare bright spot for Democrats in Georgia after a midterm that ended in triumph for every other statewide Republican candidate, and his win prevented an outright reversal just two years after Democrats swept the U.S. Senate runoffs and helped Joe Biden win the White House.

The $401 million race, which was called by NBC, was the nation’s most expensive. The victory gives Democrats 51 seats in the Senate, meaning they can claim a majority on committees and exert more influence without having to depend exclusively on Vice President Kamala Harris’ tiebreaking vote.

Warnock prevailed with a strategy that mobilized both reliably liberal Democrats and middle-of-the-road voters, including many in the latter bloc who split their ticket in the first round by also voting for Republican Gov. Brian Kemp.

The senator staved off Walker’s attempts to turn the race into a referendum on Biden, whose low approval ratings complicated his campaign.