Election officials, journalists, and even Facebook have been busy preparing Americans for the likelihood of having to wait days or weeks after November 3 to know who won the presidency. Remarkably, the fate of another branch of government could take even longer to be settled. There’s a small but real possibility that the country won’t know which party controls the Senate until January. The reason? Georgia.

Georgia is the only state in the country with both Senate seats on the ballot this fall, thanks to a special election for the successor to Republican Johnny Isakson, who resigned last year for health reasons. It’s also one of only two states (the other is Louisiana) that require candidates to hit 50 percent of the vote in order to avoid a general election runoff—a relic of the Jim Crow era, when Southern Democrats schemed to prevent Black voters from uniting behind a candidate and winning with a plurality of the vote. In neither race is any candidate polling above 50 percent right now. Should that pattern hold through the election, both races would head to a runoff, to be held January 5, two days after the new Congress is sworn in. (The rest of it, anyway.)

In one race, Democrat Jon Ossoff is challenging incumbent Republican David Perdue. Ossoff may be best known for losing the most expensive House race in US history, in 2017, but he has an outside chance at scoring an upset. Most polls show Perdue with a low-single-digit lead, and no recent poll has either candidate cracking 50 percent. (Hurting the incumbent’s chances of winning outright: A Libertarian candidate is polling in the low single digits.)

If a runoff is a possibility between Ossoff and Perdue, it’s a statistical certainty in the special election race, which currently has five major-party candidates splitting voters. The top two candidates on Election Day will advance to the runoff; most likely they will be Republican Kelly Loeffler, temporarily appointed to the seat by the governor, and Democrat Raphael Warnock, senior pastor at the Ebenezer Baptist Church in Atlanta. (There is a chance Democrats get locked out entirely, however. Warnock easily leads the two other Democrats in the race, but one of them could win enough votes to play spoiler: Matt Lieberman, the son of former senator Joseph Lieberman.)

Both races have serious implications for the next Senate. Republicans currently control 53 seats to Democrats’ 47. Assuming Joe Biden wins the presidency, Democrats will need to add three seats to achieve a 50-50 tie, with Vice President Kamala Harris casting the tie-breaking vote. Since Doug Jones is probably facing defeat in Alabama, that means winning four seats currently held by Republicans. If Donald Trump is reelected, however, Democrats will need five new Senate seats.

There are currently four races where Democrats lead Republican incumbents consistently in the polls. The 538 forecast currently gives Democrats a 62 percent chance of controlling the Senate, and sweeping the four seats where they’re currently ahead is only one of several scenarios, each individually unlikely, in which that would happen. That means control of the chamber could well hinge on other competitive states, like Georgia. If it turns out that both Georgia seats are still undecided after November, the Senate could easily be tied at 49-49, or one party could lead, 50-48, heading into January 5. The chances of either a Biden or Trump administration executing any significant part of its agenda could all hinge on what happens in what would be, essentially, a statewide vote for control of the federal government. Even if one party already has a majority, the double-election scenario would still be consequential. The prospects for meaningful climate legislation, for example, could turn on whether it requires the vote of West Virginia’s Joe Manchin, the most conservative Democrat in the Senate, to get over the majority hump.