Democrats will retain control of the Senate next year, having picked up seats in Massachusetts, Indiana and Maine along with holding on to several of their endangered incumbents who were in tough races.
It's a switch from the beginning of the cycle, when the party was seen as in trouble as they were defending more seats than Republicans.
But the recruitment of strong candidates and several gaffes on behalf of GOP challengers helped Democrats keep the upper chamber.
National Republican Senatorial Committee chairman Sen. John CornynJohn CornynTrump wall faces skepticism on border No Congress members along Mexico border support funding Trump's wall Obama-linked group launches ads targeting Republicans on immigration MORE (R-Texas) said the results meant the GOP needed to do some soul-searching.
"It’s clear that with our losses in the Presidential race, and a number of key Senate races, we have a period of reflection and recalibration ahead for the Republican Party. While some will want to blame one wing of the party over the other, the reality is candidates from all corners of our GOP lost tonight. Clearly we have work to do in the weeks and months ahead," he said in a statement.
He also warned Democrats that "they should not over-read their mandate as reflected by the almost evenly-divided popular vote."
Senate Majority Leader Harry ReidHarry ReidWarren builds her brand with 2020 down the road 'Tuesday Group' turncoats must use recess to regroup on ObamaCare Dem senator says his party will restore 60-vote Supreme Court filibuster MORE (D-Nev.), who will keep his spot in the 113th Congress, extended an olive branch to House Speaker John BoehnerJohn BoehnerLobbyists bounce back under Trump Business groups silent on Trump's Ex-Im nominee Chaffetz won't run for reelection MORE (R-Ohio) and Senate Republican Leader Mitch McConnellMitch McConnellFive fights for Trump’s first year Warren builds her brand with 2020 down the road AACR’s march on Washington MORE (R-Ky.).
“I look at the challenges that we have ahead of us and I reach out to my Republican colleagues in the Senate and the House. Let’s come together. We know what the issues are, let’s solve them,” he told a boisterous audience packing the ballroom of the Liaison hotel, where Democratic congressional leaders were spending election night.
They had much to celebrate.
The party had a major victory with Democrat Elizabeth WarrenElizabeth WarrenWarren builds her brand with 2020 down the road Warren: Trump 'all talk' on Wall Street Dem senators ask Bannon for more info about Breitbart contact MORE's victory in Massachusetts over Republican Sen. Scott Brown. Both parties were heavily invested in the race: Democrats wanted to win back the seat once held by the late-Sen. Edward Kennedy (D-Mass.), and Republicans desperately wanted to hold it.
Democrats also picked up seats in Indiana and in Maine.
Rep. Joe DonnellyJoe DonnellyGOP rep to potential Senate rival: Don't run Trump’s Army pick faces tough confirmation fight Senate Dems target potential GOP candidates over ObamaCare repeal MORE (D-Ind.) beat Republican Richard Mourdock, who defeated longtime Sen. Dick Lugar in the GOP primary. Mourdock hurt himself with controversial comments about his opposition to abortion in cases of rape or incest.
In Maine, Independent candidate Angus KingAngus KingRepublican Sen. Collins considering run for Maine governor in 2018 Conway: Dems should listen to their constituents on tax reform Sen. King: Trump needs Congress to sign off on new military action MORE won and is expected to caucus with the Democrats, which would turn retiring Sen. Olympia Snowe's (R-Maine) seat blue.
Meanwhile, Sens. Claire McCaskillClaire McCaskillFive takeaways from the Georgia special election Picking 2018 candidates pits McConnell vs. GOP groups Potential McCaskill challenger has .7M: report MORE (D-Mo.) and Sherrod BrownSherrod BrownFive things to know about Trump's steel order Trump administration investigating effect of steel imports on US Mexico: Recent deportations 'a violation' of US immigration rules MORE (D-Ohio), both top GOP targets, won reelection. McCaskill, who was considered one of the most vulnerable Democrats earlier this year, was boosted by GOP rival Todd Akin's controversial comments on rape.
And Democrat Tim KaineTim KaineDemocrats thought they could produce a political earthquake in Kansas Poll: Dems hold double-digit leads in Virginia governor race Sen. King: Trump needs Congress to sign off on new military action MORE won in Virginia, defeating former GOP Sen. George Allen, to keep retiring Sen. Jim Webb's (D-Va.) seat. Rep. Martin HeinrichMartin HeinrichSenate Dems want Trump to release ethics waivers, visitor logs Senate Dems offer bill to restore internet privacy rules Overnight Cybersecurity: Rice denies wrongly unmasking Trump team | Dems plead for electric grid cyber funds | China reportedly targeting cloud providers MORE (D-N.M.) won his contest, keeping retiring Sen. Jeff Bingaman's (D-N.M.) seat in Democratic hands.
Polls have closed in Montana and North Dakota — where two competitive contests have not been called. But even if the GOP picks up the two states, it would not be enough to hand them control of the upper chamber. Republicans needed a net gain of four seats — since President Obama won reelection — to take control of the upper chamber.
Republican Rep. Rick Berg said late Tuesday night he will not concede the North Dakota Senate race to Democrat Heidi HeitkampHeidi HeitkampBusiness groups silent on Trump's Ex-Im nominee Sanders supporter to run against red-state Democrat GOP lays out regulatory reform wish list MORE until the state completes its recount process, which would be next Tuesday. The race between the two is tight with Heitkamp up by nearly 3,000 votes with about 98 percent of the state reporting early Wednesday morning.
Democrats also held onto Connecticut's Senate seat and Wisconsin's Senate seat. Rep. Chris MurphyChris MurphyUS to step up support for Saudis, says Pentagon chief Dem senator: Trump 'politicizing' position of Surgeon General Top financial services lobbyist departs for trade association MORE (D-Conn.) defeated Republican Linda McMahon, who also lost a Senate bid in 2010. Sen. Joe Lieberman, an Independent who caucuses with Democrats, is retiring. In Wisconsin, Rep. Tammy BaldwinTammy BaldwinLawmakers talk climate for Earth Day, Science March Trump says he supports Dem ‘Buy America’ bill Picking 2018 candidates pits McConnell vs. GOP groups MORE (D) defeated Republican Tommy Thompson, the popular former governor. Sen. Herb Kohl (D-Wis.) is retiring.
And Sen. Bill NelsonBill NelsonBipartisan group demands answers on United incident Is Congress encroaching on Americans' Internet privacy? Trump's Labor pick endorsed by Hispanic lawyers MORE (D-Fla.) won reelection, defeating Republican Rep. Connie Mack.
The Connecticut seat looked more promising for the GOP as the election approached. McMahon ran a strong campaign — much better than her 2010 effort — and was gaining on Murphy in the polls. In Florida, Republicans had hoped for a stronger candidacy from Mack.
Republicans made a strong push for Thompson in Wisconsin, with GOP running mate Paul RyanPaul RyanPelosi: 'Of course' Dems can be against abortion Five fights for Trump’s first year Sunday shows preview: Trump stares down 100-day mark MORE and Republican National Committee Chairman Reince Priebus campaigning for him. But Thompson faced a tough GOP primary from which he emerged broke and exhausted.
Sen. Bob CaseyBob CaseyPennsylvania GOP rep announces bid for Casey's Senate seat We need to pass the Anti-Semitism Awareness Act to fight hate and bigotry At the table: The importance of advocating for ABLE MORE Jr. (D-Pa.), who faced a tough, last-minute surge from wealthy businessman Tom Smith, also won reelection. Rep. Mazie HironoMazie HironoDem lawmaker to Sessions: 'You are a racist and a liar' March for Science rallies draw huge crowds around US Dems knock Trump on Earth Day MORE (D-Hawaii) defeated Republican Linda Lingle, holding on to retiring Sen. Daniel Akaka's (D-Hawaii) seat for Democrats.
One bright spot for the GOP was in Nebraska, where Republican Deb FischerDeb FischerSenators press the FCC on rural broadband affordability Smart investments in America’s future The Hill's 12:30 Report MORE beat former Sen. Bob Kerrey (D-Neb.), taking retiring Sen. Ben Nelson's (D-Neb.) seat for her party. Also Rep. Jeff FlakeJeff FlakeTrump wall faces skepticism on border No Congress members along Mexico border support funding Trump's wall Obama-linked group launches ads targeting Republicans on immigration MORE (R-Ariz.) defeated Democrat Richard Carmona in a tough race to keep retiring Sen. Jon Kyl's (R-Ariz.) seat. And Sen. Dean HellerDean HellerObama-linked group launches ads targeting Republicans on immigration Nevada Dem rep considering Senate run against Heller Vulnerable GOP senator faces rancorous town hall MORE (R-Neb.) won against Rep. Shelley Berkley (D-Nev.).
Sens. Joe ManchinJoe ManchinPicking 2018 candidates pits McConnell vs. GOP groups Manchin: Trump should make his clothes in West Virginia Sanders supporter to run against red-state Democrat MORE (D-W.V.), Ben CardinBen CardinLawmakers talk climate for Earth Day, Science March Live coverage: March for Science rally is underway Dems outraged over Spicer's Holocaust remarks MORE (D-Md.), Tom CarperTom CarperDems probe claims of religious bias in DHS 'trusted traveler' program Senate Dems want Trump to release ethics waivers, visitor logs Medicare’s coverage decisions need more input from physicians MORE (D-Del.), Sheldon WhitehouseSheldon WhitehouseDem senators ask Bannon for more info about Breitbart contact Senate Dems want Trump to release ethics waivers, visitor logs Senators offer bill to boost police training in cyber crime MORE (D-R.I.), Amy KlobucharAmy KlobucharWyden pushing to mandate 'basic cybersecurity' for Senate Senators press the FCC on rural broadband affordability Senators should stop trying to turn the Supreme Court into reality TV MORE (Minn.), Kirsten GillibrandKirsten Gillibrand Dems urge Trump to include Northeast Corridor tunnel project in infrastructure bill Dems petition FDA to ban potentially toxic chemical from shampoos, body wash Trump’s Army pick faces tough confirmation fight MORE (N.Y.), Dianne FeinsteinDianne FeinsteinHotel industry details plans to fight Airbnb Congress needs a do-over on fraud-laden 'Immigrant Investor' program Ginsburg appears to refer to Graham as one of 'the women of the Senate' MORE (Calif.), Maria CantwellMaria CantwellReport: GOP lawmakers selling access to top staffers Bipartisan group demands answers on United incident Cohn backs modern version of Glass-Steagall: report MORE (Wash.), Bob MenendezRobert MenendezTaiwan deserves to participate in United Nations The way forward on the Iran nuclear deal under President Trump Corruption trial could roil NJ Senate race MORE (N.J.), and Debbie StabenowDebbie StabenowMedicare’s coverage decisions need more input from physicians Members help package meals at Kraft Heinz charity event in DC Senate braces for fallout over Supreme Court fight MORE (Mich.) all won reelection, as did Republican Sens. Bob CorkerBob CorkerGroups warn of rural health 'crisis' under ObamaCare repeal Ringing the alarm in Congress: 20 million lives at risk due to famine Senators want more efficient way to get food aid to Africa MORE (Tenn.), Roger WickerRoger WickerPicking 2018 candidates pits McConnell vs. GOP groups McConnell’s shining moment As US healthcare changes, preventative screenings can't stop MORE (Miss.), Orrin HatchOrrin HatchChaffetz's campaign arm registers 2028 websites The Hill's 12:30 Report Chaffetz won't run for reelection MORE (Utah) and John BarrassoJohn BarrassoPoll: Sanders most popular senator in the US The animal advocate Trump climate move risks unraveling Paris commitments MORE (Wyo.).
Republican candidate Ted CruzTed CruzWarren builds her brand with 2020 down the road Trump wall faces skepticism on border No Congress members along Mexico border support funding Trump's wall MORE, a Tea Party favorite, won a Texas Senate seat.
— This story was originally posted at 8:12 p.m. and last updated at 3:24 a.m.