Democrats will hold on to Senate majority

Democrats held their Senate majority Tuesday even as they lost control of the House. 

While the party suffered a crushing defeat in the lower chamber, it won the most important Senate race of the night in Nevada, where Senate Majority Leader Harry ReidHarry ReidSatanists balk at Cruz comparison Cory Booker is Clinton secret weapon Overnight Energy: Dems block energy spending bill for second day MORE (D-Nev.) surprised many pundits by defeating Republican Sharron Angle. 

Wins by Reid and Sen. Barbara BoxerBarbara BoxerCarter pledges probe of sex assault testimony Senate panel backs B water bill with Flint aid The Hill's 12:30 Report MORE (D-Calif.), who defeated Republican Carly Fiorina in California, ensured the party would hold at least 51 seats with contests in a few states too close to call. 

It's the first time a party has held on to the Senate while losing the House since 1930.

Democrats earlier on Tuesday night won key victories in West Virginia, Connecticut and Delaware, where Republican Christine O'Donnell's primary victory over a centrist Republican lawmaker might have cost the GOP a seat. 

Republicans defeated Sens. Russ Feingold (D-Wis.) and Blanche Lincoln (Ark.) and won President Obama's old Senate seat when Rep. Mark KirkMark KirkElizabeth Warren stumps, raises funds for Duckworth GOP blocks slate of Obama judicial nominees Durbin: McConnell should move criminal justice bill next month MORE (R) pulled out a victory in Illinois. 

The GOP also won Pennsylvania, where former GOP Rep. Pat Toomey defeated Democratic Rep. Joe Sestak. Toomey will succeed Sen. Arlen Specter, who bolted for the GOP in 2009 only to lose in a primary to Sestak. 

The GOP also picked up seats in North Dakota and Indiana where Democrats retired. 

The two parties were locked in a tight contest in Colorado, where appointed Sen. Michael BennetMichael BennetGOP Senate candidate wins right to be on Colorado ballot EPA ozone rule looms large in swing state 2 Colorado Senate candidates fail to qualify for ballot MORE (Colo.) is trying to hold on against Republican Ken Bush. 

Another close race is Washington, where Democratic Sen. Patty MurrayPatty MurrayOvernight Healthcare: Medicare fight looms on Capitol Hill Senate GOP hardening stance against emergency funding for Zika Overnight Healthcare: More trouble for Zika funding MORE (D-Wash.) is in a battle with Republican Dino Rossi. 

Manchin was able to defeat Republican John Raese, who at one point had held a lead in polls, by running as far as possible from President Obama to highlight his independence. Manchin even filmed an advertisement where he put a rifle shot through a copy of the cap-and-trade bill. 

Democrat Chris CoonsChris CoonsInvestments in research and development are investments in American jobs House clears trade secrets bill for Obama's signature Senators aim to bolster active shooter training MORE was projected to win Vice President Joe BidenJoe BidenIf you’re going to meet with Merrick Garland Biden on cancer research: 'I’ve been on the other end of the need' The Hill's 12:30 Report MORE's old Senate seat in Delaware over Tea Party-favorite O'Donnell. 

O’Donnell's upset of Rep. Mike Castle (R) in Delaware’s primary dimmed GOP hopes of winning the Senate. Castle was a clear favorite against Coons, but O’Donnell entered the general election as a heavy underdog.

The major networks called Democratic Attorney General Richard BlumenthalRichard BlumenthalLawmaker calls for probe into 'unusual' Amazon cruise deaths Carter pledges probe of sex assault testimony FDA should ban powdered caffeine, Dems say MORE the winner in Connecticut over Republican Linda McMahon. Blumenthal held on to retiring Sen. Chris Dodd's (D) seat.

Republicans got off to a good start Tuesday after picking up a seat in Indiana and watching Tea Party-favorite Rand PaulRand PaulCarter pledges probe of sex assault testimony Rand Paul wants to legalize cooperation Dem fears Iran nuke deal gives license to back Saudis MORE win Kentucky. 

Former Sen. Dan CoatsDan CoatsGOP blasts Obama for slow economic growth GOP Senate candidate failed to report private plane trip from Ind. supporter Overnight Finance: Fed steady on rates; Dems rally behind retirement rule MORE beat Democratic Rep. Brad Ellsworth in Indiana to win the seat now held by Democratic Sen. Evan Bayh. Republicans also took out Sen. Blanche Lincoln (D), who saw her popularity fall during the debate over healthcare reform. Rep. John BoozmanJohn BoozmanBringing US rice back to Cuba Senate passes energy reform bill Capitol Hill’s forest champions helped secure win for wood MORE (R), who led in polls throughout the race, defeated Lincoln. 

Feingold wasn't on most lists of likely Democratic casualties a few months ago, but he ran into a buzzsaw in Republican businessman Ron JohnsonRon JohnsonSenators urge White House to speed cyber policy updates Mellman: Fissures and factions Encryption commission bill picks up more backers MORE, who soared ahead in polls and appeared on the way to a relatively easy victory on Tuesday night.

Republicans also held on to seats in Ohio and Florida, where the GOP's Marco RubioMarco RubioRubio: Trump has 'improved significantly' House GOP campaign arm accuses '60 Minutes' of trespassing Republicans who vow to never back Trump MORE looks to be in for a huge win over Gov. Charlie Crist, who left the Republican Party to run for the Senate as an independent. 

In Ohio, Republicans held a seat when Rob PortmanRob PortmanJohn Bolton PAC pours more cash into GOP campaigns Dem campaign arm: Poll numbers slipping for vulnerable Republicans GOP senator jokingly calls Sherrod Brown 'Mr. Vice President' MORE was declared the winner over Democrat Lee Fisher, the state's lieutenant governor. 

Republicans expected to win Indiana as well as North Dakota, where Gov. John HoevenJohn HoevenThis week: Congress on track to miss Puerto Rico deadline Week ahead: Senate looks to wrap up energy, water spending bill Overnight Energy: Senate blocks GOP bill targeting water rule MORE (R) won the seat being vacated by the retiring Sen. Byron Dorgan (D). They also had long expected to win Arkansas. 

Democrats expected to win Delaware and Connecticut despite a serious campaign stumble by Blumenthal, who had suggested he'd served in Vietnam even though his military services was all stateside. Blumenthal still hung on in Democratic-leaning Connecticut to defeat McMahon, a former executive with World Wrestling Entertainment whose industry might have hurt her.

The cycle began with Democrats hoping to win Senate seats in several Republican strongholds, but it became clear relatively early that Democrats would be on defense.

The best chance for Democrats to win back a seat may be Alaska, where GOP Sen. Lisa MurkowskiLisa MurkowskiThe Hill's 12:30 Report Bishop eyes new Puerto Rico bill after recess Week ahead: Senate looks to wrap up energy, water spending bill MORE’s write-in bid could lift Democrat Scott McAdams to an unlikely win. Republican nominee Joe Miller, who bested Murkowski in the primary, could now split the vote with her. 

The result from that race might not be known for days, and some are already expecting re-counts and legal challenges.

Paul and Portman, two of the big GOP winners, represent different ends of the Republican Party in some ways. 

While Paul had support from grassroots Republicans and defeated an establishment candidate, Democrats thought Portman, a former congressman, could be vulnerable because of his ties to the GOP establishment, specifically the Bush administration. 

But Portman, who will succeed retiring Sen. George Voinovich (R), led throughout the race.

This story was first posted at 7:27 p.m. and last updated at 3:12 a.m.