In what could be a disappointing night for Democrats, the chances of their taking the Senate fell as Republican incumbents held seats.Congressional seats in both the House and Senate are up for grabs.Chelsea Stahl / NBC NewsNov. 3, 2020, 8:25 PM UTC / Updated Nov. 4, 2020, 8:05 PM UTCBy Sahil Kapur

WASHINGTON — Democrats will maintain control of the House of Representatives, NBC News projects, but their path to taking control of the Senate has narrowed significantly as numerous Republican incumbents fended off strong opposition.

Democrats failed to pick up some of the Senate seats they were banking on to capture a majority. Their hopes for a big night were dashed up and down the ballot, as President Donald Trump outperformed his polls against Joe Biden in a race still to be decided.

In Maine, Republican Sen. Susan Collins was declared by NBC News as the apparent winner.

Other GOP senators who were Democratic targets hung on: Iowa Sen. Joni Ernst, Montana Sen. Steve Daines and South Carolina Sen. Lindsey Graham were all re-elected, NBC News projected.

By Wednesday afternoon, 48 Senate seats were projected to be controlled by Republicans and 46 by Democrats, including two independents who caucus with Democrats.

Adding some uncertainty, the Georgia special election is headed to a runoff on Jan. 5 between Democrat Raphael Warnock and Republican Sen. Kelly Loeffler, NBC News projects.

Democrats will pick up a Senate seat in Colorado as John Hickenlooper is projected by NBC News to unseat Republican Sen. Cory Gardner, marking the party’s first gain.

Offsetting that, Republicans will pick up a seat in Alabama, where Republican Tommy Tuberville is projected to defeat Democratic Sen. Doug Jones, NBC News projects.

In Arizona, the Democratic challenger Mark Kelly leads but NBC News rates it “too early to call.”

In North Carolina, Republican Sen. Thom Tillis leads Democrat Cal Cunningham narrowly but the race is rated “too close to call.”

Democrats still have a path to 50 seats, but it’s a narrow one: It requires winning Arizona, where they lead, and both Georgia races. The second Georgia race is rated “too close to call.” It also requires holding on to the seat of Sen. Gary Peters, D-Mich., in a race rated “too early to call.”

Graham claims he's 'never been challenged like this' after Senate victoryNov. 4, 202001:52

Democrats largely focused their campaigns on protecting the Affordable Care Act and stepping up efforts to combat the coronavirus. Republicans mostly focused on the economy and preventing a Democratic-led Senate that could pursue progressive legislation in a potential Biden presidency.

Two top Republicans — Sen. Mitch McConnell of Kentucky and Sen. John Cornyn of Texas — will be re-elected, NBC News projects. Sen. Chris Coons, D-Del., Sen. Ed Markey, D-Mass., Sen. Cory Booker, D-N.J., Sen. Jeanne Shaheen, D-N.H., Sen. Shelley Moore Capito, R-W.V., Sen. Bill Cassidy, R-La., and Sen. James Inhofe, R-Okla., will be re-elected, NBC News projects. All were heavily favored.

Republicans held open seats in Wyoming and Kansas with victories by their candidates Cynthia Lummis and Roger Marshall, respectively, according to NBC News projections.

And Democrat Ben Ray Lujan won an open seat in New Mexico, keeping the state for Democrats.

35 Senate seats up for grabs in battle for Senate controlNov. 3, 202002:11Alabama

Democrat Jones surprised political pundits when he won the seat in a special election but was unable to fend off retired football coach Tuberville in a deep-red state where the Republican is heavily favored.

Michigan

Michigan is seen as the GOP’s only other possible pickup opportunity, where Iraq War veteran John James is trying to unseat Peters, who is the favorite.

Maine

Republican Collins has served in the chamber for 24 years and faced the fight of her political life with a challenge from Gideon, speaker of the state House.

Collins’ vote to confirm Supreme Court Justice Brett Kavanaugh became a rallying cry for Gideon, who has argued that Collins lost the independence she previously touted.

Colorado

Republican Gardner lost to Hickenlooper, a popular former governor. Hickenlooper, who made a failed bid for the Democratic nomination for president, was popular in the state when he left office. Hickenlooper led by about 10 points with 87 percent of the vote counted.

Arizona

Republican Martha McSally, who was appointed to fill the seat after the death of John McCain, faces off against Democratic former astronaut Kelly.

North Carolina

The closely-watched race was roiled by Tillis catching Covid-19 and then his Cunningham getting caught sending romantic text messages to a woman who isn’t his wife.

Iowa

Republican Ernst defeated Democrat Theresa Greenfield in a neck-and-neck race that could be a bellwether for the majority. Ernst led by about 6 percentage points with 91 percent of the vote in.

Georgia

Georgia voted in two Senate races.

Republican Sen. David Perdue faced an unexpectedly competitive challenge from Democrat Jon Ossoff.

The second race is a special election. Loeffler, who was appointed to the seat, will face Warnock in a runoff in January.

Montana

Republican Daines fended down the state’s Democratic governor Steve Bullock. After saying he wasn’t interested in running for the Senate, Bullock changed his mind after a failed bid for the presidential nomination.

South Carolina

Graham defended his seat against Democratic opponent Harrison in a race that had unexpectedly been polling closely. Harrison smashed fundraising records, allowing him to advertise aggressively to unseat Graham, who has become a close ally and staunch defender of Trump.

Texas

Cornyn fended off an effort by Democrat MJ Hegar to capitalize on suburban shifts toward Democrats and blockbuster fundraising numbers.

Kentucky

McConnell defeated a challenge from Democrat Amy McGrath, a former fighter jet pilot who raised about $88 million.