Republican Alaska Sen. Dan Sullivan won reelection Tuesday, multiple outlets reported.

Sullivan, who was first elected in 2014, was ahead of Independent Al Gross by 20 points when the race was called, leading 57% to 37%.

Though Sullivan held a small but consistent lead over Gross, the race narrowed in the final weeks before the election, polls showed. Gross’s campaign also out-raised Sullivan’s in the campaign’s final months, announcing a $9 million haul in October.

Gross, an orthopedic surgeon who highlighted his Alaskan upbringing in his campaign ads, repeatedly attacked Sullivan for his allegiance to President Donald Trump. Though officially an Independent, Gross said that he would caucus with the Democrats if elected.

Sullivan’s win gives the GOP at least 50 Senate seats for the 117th Congress. The only races that remain to be called are in Georgia, where incumbent GOP Sens. David Perdue and Kelly Loeffler advanced to January runoffs against Democratic challengers Jon Ossoff and Rev. Raphael Warnock, respectively. (RELATED: Stacey Abrams Says Democrats Can ‘Absolutely’ Win Georgia Runoffs)

If Perdue and Loeffler prevail, the GOP will have a 52-48 senate majority, which would likely prevent President-elect Joe Biden from passing much of his agenda. If both seats flip, however, the Senate will be split 50-50, meaning that Vice President-elect Kamala Harris would serve as a possible tie-breaking vote.