Control of the Senate remained unknown as ballots continued to be counted Wednesday and some races were projected to remain undecided for days or even weeks. 

That’s a disappointment for Democrats, who went into the night expecting to have several routes to the majority, including potential wins in traditionally conservative states that President Donald Trump carried in 2016. Those hopes were deflated early on, with Republican wins in South Carolina, Texas, Kansas, Iowa and Montana, despite facing well-funded Democratic challengers. 

But Democrats still have a narrow path to the majority after flipping two Senate seats in Arizona and Colorado, ousting Sens. Martha McSally and Cory Gardner. Republicans have flipped just one Senate seat, with Alabama Democratic Sen. Doug Jones losing to former Auburn University football coach Tommy Tuberville.

Democrats need a net gain of three or four seats to win the majority, depending on who wins the White House, because the vice president breaks ties in a 50-50 Senate.

The Associated Press has yet to call Senate races involving Republican Sen. Thom Tillis‘ race in North Carolina or in Sen. David Perdue‘s battle with Democrat Jon Ossoff in Georgia. The AP has also not called the race in Michigan, where Democratic Sen. Gary Peters faces GOP Army veteran John James.

Maine Sen. Susan Collins said Wednesday afternoon that her opponent, state House Speaker Sarah Gideon, had called to concede, and the AP called the race about an hour later, when returns showing her with less than 51 percent to Gideon’s 42 percent.

“I feel this is an affirmation of the work I’m doing in Washington,” Collins told a crowd gathered in Bangor. 

Former Vice President Joe Biden was projected to be the winner in Maine by the AP early Wednesday, but the presidential race result in Michigan, Georgia and North Carolina was still uncalled.

If neither Perdue nor Ossoff gets over 50 percent, they will have to face each other again in a runoff on Jan. 5. There is already going to be a runoff in the other Senate election in Georgia, a special election to fill the last two years of former Sen. Johnny Isakson’s term. That race will pit appointed Sen. Kelly Loeffler and Democratic pastor Raphael Warnock.

Pre-election polls showed Warnock slightly leading Loeffler in a hypothetical runoff, but strategists in both parties said the dynamics of such a matchup would be hard to predict. Republicans traditionally hold an advantage in runoff races in Georgia, but Democrats have been steadily increasing their electoral power in the state, and outside groups on both sides can be expected to pour tens of millions of dollars into the race if control of the Senate hangs in the balance. 

Jessica Wehrman contributed to this report.