The Senate Republicans' campaign arm is throwing its support behind Kari Lake in battleground Arizona's crucial race, a contest that could determine if the GOP wins back control of the chamber in November.

Tuesday's announcement by National Republican Senatorial Committee chair Sen. Steve Daines is the latest sign that Lake is moving past her outsider and fiery election-denial-centered 2022 campaign for Arizona governor and is capable of working with the GOP establishment.

"Kari Lake is one of the most talented candidates in the country. Kari is building out an effective campaign operation that has what it takes to flip Arizona’s Senate seat in November. I’m proud to endorse Kari Lake for United States Senate," Daines, the Republican senator from Montana who is chairing the NRSC this cycle, said in a statement.

THE TOP FIVE SENATE SEATS LIKELY TO FLIP IN NOVEMBER

Republican Arizona Senate candidate Kari Lake

Former Arizona Republican gubernatorial candidate Kari Lake announces her bid for the seat of Sen. Kyrsten Sinema on Oct. 10, 2023, in Scottsdale. (Rebecca Noble/Getty Images)

Lake is a former longtime local TV news anchor in Arizona who's a strong supporter of former President Donald Trump and his unproven claims his 2020 election loss to President Biden was due to massive voter fraud. She sparked plenty of controversy in her narrow 2022 gubernatorial election loss. Lake never conceded her more than 17,000-vote defeat and repeatedly and unsuccessfully challenged the results in court.

But since announcing her Senate bid last October, Lake has consistently courted the NRSC and establishment Republicans, most recently last weekend at the campaign committee's winter meeting in Palm Beach, Florida.

"I am honored to have the endorsement of Chairman Daines and the NRSC," Lake said in a statement, which was first reported by Politico. "We are uniting Republicans in Arizona and have a clear path to victory. The Senate Majority runs through Arizona."

FIRST ON FOX: TOP SENATE REPUBLICAN TO BOOST LAKE WITH KEY ENDORSEMENT

Daines and the NRSC have been much more hands on in GOP Senate primaries – in candidate recruitment and efforts to dissuade others from running – in comparison to the committee during the 2022 cycle under then-chairman Sen. Rick Scott of Florida.

Steve Daines

Sen. Steve Daines speaks to reporters at the U.S. Capitol on Feb. 9, 2023. (Drew Angerer/Getty Images)

The NRSC backed candidates Tim Sheehy in Montana and Dave McCormick in Pennsylvania as they launched their campaigns. But while Daines has complimented Lake in recent months, he has waited until now for an official endorsement.

In Arizona, Lake faces a nominal rival in Pinal County Sheriff Mark Lamb, and she's considered the overwhelming favorite to win the nomination.

Fox News has confirmed that the NRSC will host a fundraiser for Lake on March 6, which will be attended by Daines as well as Sen. John Barrasso of Wyoming, the Senate GOP Conference chair.

Barrasso, the number three Republican in Senate GOP leadership, had previously endorsed Lake and plans to campaign with her in Arizona on Feb. 29.

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Democrats control the U.S. Senate with a 51-49 majority, but Republicans are looking at a favorable Senate map this year, with Democrats defending 23 of the 34 seats up for grabs. Three of those seats are in red states that Trump carried in 2020 – West Virginia, Montana and Ohio.

Five other blue-held seats are in key swing states narrowly carried by President Biden in 2020 – Arizona, Michigan, Nevada, Pennsylvania and Wisconsin.

Current/Potential Arizona Senate candidates

From left, Republican Pinal County, Arizona, Sheriff Mark Lamb, Rep. Ruben Gallego, D-Ariz., Sen. Kyrsten Sinema, I-Ariz., and former gubernatorial candidate Kari Lake (Getty Images)

Once reliably red, Arizona has become a key southwestern general election battleground state.

The state narrowly voted in 2018 for then-Democratic Rep. Kyrsten Sinema in a crucial Senate race, and for President Biden and Democratic Sen. Mark Kelly in 2020.

Lake was narrowly defeated for governor in 2022, while Kelly won election to a full six-year term in the Senate by five points.

This year's Senate election in Arizona remains complicated as Sinema, who is now an independent, has not yet decided whether she will run for re-election.

Rep. Ruben Gallego is the frontrunner for the Democratic Senate nomination, and the possibility of a three-way contest with Sinema, Gallego and Lake has some Republicans salivating.

The Democratic Senatorial Campaign Committee took aim at their GOP counterpart and at Lake following the news.

"Kari Lake is the poster child for Senate Republicans' candidate quality problem and abysmal recruiting strategy, DSCC spokesperson Tommy Garcia charged in a statement. "An election loser despised by Arizona Republicans, Lake brings massive baggage and disqualifying flaws to the campaign. We're thrilled with the NRSC's choice. Lake is the perfect candidate - to lose the race."

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