Rep. Bill Cassidy (R-La.) easily ousted incumbent Sen. Mary LandrieuMary Loretta LandrieuSenate GOP rejects Trump’s call to go big on gun legislation Project Veritas at risk of losing fundraising license in New York, AG warns You want to recall John McCain? Good luck, it will be impossible MORE (D-La.) in their Senate runoff on Saturday, capping off a dominating midterm election for Republicans.  

The GOP’s victory in the final race of the 2014 cycle cements their nine-seat pickup in the upper chamber, giving them a 54 to 46 advantage over Democrats come January. Though Senate control wasn’t in the balance, Cassidy’s win is nonetheless an exclamation point on a midterm cycle that saw big gains for Republicans. 

Polls in Louisiana closed at 9 p.m. EST, and the Associated Press called the race in favor of Cassidy at 9:30 pm with only 40 of the 4,018 precincts reporting and the Republican with a 64 percent to 36 percent lead.

Landrieu was upbeat in her concession speech later Saturday evening, taking the stage smiling and laughing with family members and supporters.

"I just called Congressman Cassidy to congratulate him after a long and tough campaign,” she said. “I told him that representing the people of this state is the greatest honor that anyone could ever have.”

Still, she seemed to take a swipe at Cassidy, who her campaign accused of hiding from voters and the media in the final days before the election.

 “The people of our state have spoken, and while we were working and hoping and praying for a different outcome, I’m so proud that our campaign was open and accessible to voters,” she said.

Landrieu ticked off what she called her greatest accomplishments while in the Senate – securing the Louisiana coast line, boosting the military bases in the state, and strengthening the foster care system.

But her biggest round of applause came for her strong defense of her vote for the Affordable Care Act.

“This is something to be proud of and I’m glad we fought for it,” she said.

In his victory speech at the Crowne Plaza Hotel in Baton Rouge, Cassidy said Landrieu “graciously” congratulated him and wished him and his family well. 

“Sen. Landrieu should be thanked, and we all do, for her service to our country,” he said. “My message to those who supported Sen. Landrieu is…that I don’t care that you voted for Sen. Landrieu, I’m here to represent you too. We can unite as a state.” 

Still, Cassidy was triumphant, and touted his win as “an exclamation mark” on the midterm elections and evidence that the country is moving “in a conservative direction.”

“We the people have the power, not the federal government,” he said. “You have sent that message, thank you very much.”

Landrieu was an underdog in the runoff election from the start. In the Nov. 4 jungle primary, Landrieu edged Cassidy 43 to 42, but he split the Republican vote with Tea Party candidate Rob Maness, who took 14 percent.

Landrieu didn’t get any help from national Democrats, who effectively abandoned her by pulling the money they had allocated for the race. The backbiting among Democrats who are upset that the Democratic Senatorial Campaign Committee left her massively outgunned on the airwaves has already begun.

“Mary Landrieu is a good Senator, a Southern Democrat, and the chair of a key committee. The Democratic Party should have gone all in and fought totally and completely for her,” Brent Budowsky, a Democratic operative and columnist for The Hill, said in a phone interview. “I vehemently disagree with abandoning her that way. Democrats should fight until the last dog dies for every Democratic Senator, particularly a Southern Democrat and a committee chair, and I don’t understand why they didn’t.”

Landrieu was the last remaining Democrat in the Senate to hail from the Deep South. Sens. Kay HaganKay Ruthven HaganSenate GOP rejects Trump’s call to go big on gun legislation Politics is purple in North Carolina Democrats can win North Carolina just like Jimmy Carter did in 1976 MORE (D-N.C.) and Mark PryorMark Lunsford PryorMedicaid rollback looms for GOP senators in 2020 Cotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm MORE (D-Ark.) also lost reelection bids on Nov. 4.

With no air support, Landrieu barnstormed the state in the final days of the campaign, hitting more than a dozen towns and parishes across Louisiana with the help of some of her Democratic colleagues. She sought to spotlight allegations that Cassidy wrongly billed Louisiana State University as a part-time doctor while he was a member of Congress.

A centrist Democrat from a well-known political family in the state, Landrieu was the chairwoman of the Senate Energy and Natural Resources Committee who had won tough runoff races in deep red Louisiana in the past.

But polls showed Cassidy with a big lead heading into Election Day, and he was able to run out the clock away from the campaign trail.

Cassidy cancelled his appearances at a couple of campaign events and returned to Washington for votes on Tuesday. He returned to Louisiana for an event with Sen.-elect Joni Ernst (R-Iowa) on Friday. But on Election Day, when candidates typically seek out the media to make their closing arguments, he opted to take a professional development course instead, according to CNN.

The Landrieu campaign was hard up for good news for the entirety of the runoff period.

Landrieu stormed into Washington for the lame duck period intent on passing a bill authorizing the Keystone XL pipeline. If it worked, it could have put space between herself and an unpopular president, reminded voters of her seniority on the Energy Committee and would have been evidence she has the clout to pull together a Democratic coalition when it mattered most. 

But she fell one vote shy, while a version of the bill sponsored by Cassidy sailed through the House, giving Republicans more political ammunition against her.

 Cassidy rallied conservatives early after picking up Maness’ endorsement. Republicans held “unity rallies” across the state for Cassidy that became must-attend events for big names in the GOP, like Sen. Rand PaulRandal (Rand) Howard PaulTrump informally offered Cohn CIA job before changing his mind: report Congress moving to end US involvement in Yemen Congress races to finish .2 trillion funding bill MORE (R-Ky.) and Gov. Rick Perry (R-Texas)

Democrats and liberal groups, meanwhile, placed their bets before the runoff period. With the Senate majority no longer at stake and staring down an uphill race, national Democrats opted to sit on what little money they had left. 

Multiple analyses of ads during the runoff period showed Landrieu getting clobbered on the airwaves, with one report showing that ads from groups attacking Landrieu accounted for about 13,900 of the 14,000 TV spots that have run since the Nov. 4 jungle primary.

Democrats were hopeful their ground game would make up the difference, but after three Saturdays of early voting in Louisiana, it was Republicans, not Democrats, who increased their numbers in comparison to the early voting period before Nov. 4. The number of Democrats and black voters, with whom Landrieu has near universal support, declined.

Cassidy also won the fundraising battle during the runoff period, bringing in about half a million more than Landrieu, and entering the final week of the campaign with $1.3 million in the bank, compared to less than $800,000 for Landrieu. 

The political landscape in Louisiana and other states in the Deep South has turned sharply against Democrats as white voters have abandoned them. In her 2008 election, Landrieu took 33 percent of the white vote, but that fell to just 18 percent during the Nov. 4 jungle primary.

Some Democrats believe this isn’t the end of the road for Landrieu, though, and she  could launch a comeback bid as early as 2016. With incumbent Sen. David VitterDavid Bruce VitterTrump nominates wife of ex-Louisiana senator to be federal judge Where is due process in all the sexual harassment allegations? Not the Senate's job to second-guess Alabama voters MORE (R-La.) expected to run for governor in Louisiana, she might find a better political climate in a special election and in a presidential year with higher Democratic turnout. 

This post was updated at 11:08 p.m.