Democrats have secured the presidency for Joe Biden, but the story is a different one in the Senate. Like the White House, it was projected to turn blue, with poll analysts like FiveThirtyEight giving the chamber about a three-in-four chance of shifting to a blue majority. But that hasn’t gone as planned for Democrats, who are facing a potential reality in which the Senate remains in the hands of the GOP.

As of now, the Democrats effectively hold 48 seats in the Senate, with independents Bernie Sanders of Vermont and Angus King of Maine caucusing with the party. Because Biden was able to win the presidency, his vice president, Kamala Harris, could break a 50–50 tie in the Senate, meaning Democrats need at least two seats from the remaining four elections that are still counting ballots or facing a runoff election. Here are the races to keep an eye on:

Georgia

Any realistic shot of Democrats flipping the Senate will come down to Georgia, which has two seats up for grabs. Even if they lost the other remaining races in North Carolina and Alaska—where they currently trail— winning both seats in the Peach State would give Democrats majority control, in the event that Biden is indeed declared President-elect.

Both of these seats are going to be decided by a runoff election in January. One is between Democrat Raphael Warnock and Republican Sen. Kelly Loeffler. They advanced after failing to win a 50% majority in a 20-candidate special election, but managing to finish in the top two. With 98% of the vote reported at the time of writing, Warnock held a seven-point lead over Loeffler, though conservative votes in the race were split between her and Republican Doug Collins, who finished third.

The other Georgia race comes down to Republican incumbent David Perdue and Democrat Jon Ossoff. The former led by a couple percentage points votes with 98% of the vote counted. But, as with the other special election, Perdue didn’t earn at least 50% of the vote to avoid a January runoff. He got agonizingly close with 49.8%, but Ossoff was able to rally late with much of the final batch of votes being based in the heavily liberal Atlanta metro region. A runoff has now officially been scheduled for both races.

Biden’s victory is a significant achievement for the Democrats, but he won’t be able to implement many of his policy plans in a Mitch McConnell-led Republican Senate. This means Georgia is about to become the center of the American political universe for the next two months as both parties view for majority control.

North Carolina

This one is all but over as Democratic challenger Cal Cunningham conceded to Republican incumbent Thom Tillis on Tuesday. The remaining votes will continue to be counted, as mail-in ballots postmarked by Election Day are accepted until Nov. 12., but Republicans appear to be headed to victory.

Alaska

The GOP incumbent Dan Sullivan has a sizable 30-point lead over the independent Al Gross (backed by the Democrats), but only 58% of the vote has been counted so far. Alaska leans Republican, but it has a large number of independent voters, and many absentee ballots won’t be counted for several more days. Some observers have suggested the possibility of a Democrat upset here, and Gross himself is projecting an air of confidence. “We believe we will win once every vote has been counted in the state,” he tweeted last week.