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 ReidSanders tests Wasserman Schultz Nearly 400 House bills stuck in Senate limbo Puerto Rico debt relief faces serious challenges in Senate MORE (D-Nev.) surprised many pundits by defeating Republican Sharron Angle. 

Wins by Reid and Sen. Barbara BoxerBarbara BoxerDem senators back Interior coal leasing review Trump and Sanders whip up debate buzz Boxer: Sanders appeals to young voters with grandpa effect 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 KirkFunding boost for TSA sails through committee GOP senators propose sending ISIS fighters to Gitmo VA chief 'deeply' regrets if Disney comment offended vets 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 hopeful wants to go beyond Trump's Muslim ban Lawmakers push to elevate Cyber Command in Senate defense bill GOP ad calls Clinton 'a living history of scandal' MORE (Colo.) is trying to hold on against Republican Ken Bush. 

Another close race is Washington, where Democratic Sen. Patty MurrayPatty MurraySenate backs equal pay for female soccer players Feds can learn lessons from states about using data to inform policy Lawmakers blast poultry, meat industries over worker injuries 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 CoonsDems: Warren ready to get off sidelines Dems pressure Obama on vow to resettle 10,000 Syrian refugees Wildlife crime bill deserves unanimous consent in Congress MORE was projected to win Vice President Joe BidenJoe BidenSanders: 'Terrible idea' to turn to Biden if Clinton is indicted Clinton urged to go liberal with vice presidential pick Biden will host cancer research summit in DC 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 BlumenthalDems press ITT Tech to give students right to sue Senate amendments could sink email privacy compromise Groups urge Senate to oppose defense language on for-profit colleges 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 PaulOvernight Energy: Trump outlines 'America First' energy plan in North Dakota Overnight Regulation: GOP slams new Obama education rules Paul blocks chemical safety bill in Senate MORE win Kentucky. 

Former Sen. Dan CoatsDan CoatsDems to GOP: Cancel Memorial Day break GOP senators: Obama bathroom guidance is 'not appropriate' Overnight Defense: House panel unveils 5B defense spending bill 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 BoozmanOvernight Tech: House GOP launches probe into phone, internet subsidies Overnight Tech: Trade groups press NC on bathroom law GOP senators: Obama bathroom guidance is 'not appropriate' 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 JohnsonSunday shows preview: Bernie soldiers on Clinton email headache is about to get worse The Trail 2016: Interleague play 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 RubioSunday shows preview: Bernie soldiers on Fla. Senate candidate bashes Rubio The Hill's 12:30 Report 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 PortmanJuan Williams: Electoral map looks grim for Trump McConnell touts 'Senate squad' in Wes Anderson-style video Liberal super-PAC hits Johnson for supporting Trump 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 HoevenSenate panel approves funding boost for TSA Overnight Energy: Senate Dems block energy, water bill a third time Bison declared national mammal 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 MurkowskiSenators float bipartisan wildfire bill Overnight Energy: Lawmakers closing in on chemical safety deal GOP chair pushes Obama official on Arctic drilling plan 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.