Senate Republican Leader Mitch McConnell on Wednesday endorsed former NFL star Herschel Walker’s bid for a U.S. Senate seat in Georgia, a key battleground state the GOP hopes to flip from blue to red in next year’s midterm elections.

In doing so, the Kentucky senator joins former President Donald Trump in backing Walker, who briefly played for a Trump-owned team in the long-defunct USFL.

McConnell's move comes amid a nearly yearlong war of words between the two GOP giants over Trump’s repeated emphasis on re-litigating his 2020 election loss to now-President Biden, and his numerous calls for McConnell to be ousted as Senate Republican leader.

The senator's endorsement, which was shared first with Fox News and Politico, signals that the GOP Senate leadership – and with it much of the party establishment in the nation’s capital -- is rallying around Walker’s bid to challenge Democratic incumbent U.S. Sen. Raphael Warnock in a race next year that may determine if the GOP wins back the Senate majority in the 2022 midterms.

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"I am happy to endorse Herschel Walker for U.S. Senate in Georgia," McConnell said in a statement ."Herschel is the only one who can unite the party, defeat Senator Warnock, and help us take back the Senate. I look forward to working with Herschel in Washington to get the job done." 

McConnell endorses Herschel Walker

Senate Minority Leader Mitch McConnell, R-Ky., is seen on Capitol Hill, June 22, 2021.  (Associated Press )

Walker thanked McConnell for the endorsement and for "his commitment to bringing the party together toward the collective goal of defeating Senator Warnock. The Democrats have already said they will spend whatever it takes to keep Georgia blue. The stakes have never been higher — if we all work together, we will win next November, and take back the Senate."

Untested first-timer

Republicans close to McConnell over the summer privately briefly expressed concerns whether Walker, an untested first-time candidate with potential political baggage, would be ready for the rigors of a high-profile Senate campaign. But such talk from McConnell’s inner circle soon receded. GOP sources tell Fox News that Walker, who’s a longtime Trump ally and surrogate, has recently held what were described as a couple of "cordial conversations" with McConnell.

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McConnell becomes at least the sixth Republican senator to back Walker. And his backing comes two days after Sen. John Thune, the No. 2 Senate Republican, endorsed Walker. The support by Thune, the Senate GOP whip, came after the lawmaker from South Dakota had voiced reservations about Walker’s candidacy earlier this year.

Another lawmaker in the six-member Republican Senate leadership team, Sen. John Barrasso of Wyoming, backed Walker a couple of hours after McConnell. And  GOP sources told Fox News to expect more the coming weeks.

Walker, a former college football star running back who won a Heisman Trophy and helped propel the University of Georgia to a national championship – and later played for four NFL teams -- launched his Senate campaign in August after months of support and encouragement to run from Trump.

But his announcement came amid concerns from Republicans in Georgia and on Capitol Hill about the candidate's ability to win a crucial seat for the GOP. 

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Among the concerns was that Walker is untested under fire on the campaign trail and has not made it clear where he stands on many key issues. And those not on board with Walker’s candidacy spotlighted that Walker comes with plenty of potential political baggage that could give his opponents ammunition -- his well-documented struggles with a mental illness known as dissociative identity disorder, accusations by his ex-wife of being "physically abusive," and reports that he exaggerated the success of a food services company that he owns. 

Name recognition

The 59-year old Walker has discounted such concerns but to date has run a carefully scripted campaign since he declared his candidacy.

Walker was quickly endorsed by Trump, which along with the gridiron legend’s tremendous name recognition in Georgia boosted him to front-runner status in the GOP nomination race. And in the fundraising race, Walker sprinted out of the gates, hauling in $3.7 million from his launch through the close of September, which marked the end of the third quarter of fundraising.

Herschel Walker speaks at former President Trump's Georgia rally

Former President Donald Trump listens as Georgia U.S. Senate candidate Herschel Walker speaks during Trump's Save America rally in Perry, Ga., Sept. 25, 2021.  (Associated Press)

Walker’s fundraising easily eclipsed that of some of his rivals. Former bank executive and Navy SEAL veteran Latham Saddler brought in $1 million during the third quarter, Georgia Agriculture Commissioner Gary Black raised $564,000, and businessman and military veteran Kelvin King raised $340,000.

As Republicans aim to win back the Senate majority they lost in January when the Democrats narrowly swept Georgia’s twin Senate runoff elections, they’re playing plenty of defense, defending 20 of the 34 seats up for grabs, including five open seats – with two of them in the crucial battlegrounds of Pennsylvania and North Carolina.

Vulnerable Democrat

But they also see opportunities to flip blue seats red in four states, including Georgia. And they view Warnock as one of the most vulnerable Democrats running for reelection in 2022. 

Warnock defeated Republican Sen. Kelly Loeffler, who was appointed by GOP Gov. Brian Kemp, by a razor-thin margin on Jan. 5, to serve the final two years of the term of former GOP Sen. Johnny Isakson, who resigned in 2019 due to health reasons. 

But defeating Warnock next year won’t be easy, as Georgia’s first Black senator has set fundraising records since taking office. Warnock hauled in an eye-popping $9 million in the third quarter of this year, bringing his cash on hand to roughly $17.2 million.

McConnell’s endorsement of Walker puts him on the same page as Trump, who’s constantly berated the longtime Republican Senate leader for acknowledging Biden’s White House victory and failing to help the then-president overturn the 2020 presidential election results.

McConnell voted in February to acquit Trump, who was impeached on one count of inciting the Jan. 6 insurrection at the U.S. Capitol by protesters aiming to disrupt congressional certification of Biden’s Electoral College victory.

But McConnell assailed Trump in a speech on the Senate floor minutes after the trial concluded, saying the former president "bears moral responsibility" for the storming of the Capitol. 

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War of words

A war of words between the two GOP leaders continues to present day, with Trump continuing to urge that McConnell be ousted from his leadership position.

"The Republican Senate needs new leadership," Trump argued earlier this month in an interview with Fox News’ Sean Hannity. "Mitch is not the guy, not the right guy. He's not doing the job."

And McConnell continues to push back against Trump’s repeated unfounded claims that the 2020 presidential election was "rigged" and "stolen."

"I do think we need to be thinking about the future and not the past," McConnell told reporters on Capitol Hill last week when asked if he was comfortable with Trump’s continued dominance over the GOP.

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"I think the American people are focusing on this administration, what it’s doing to the country, and it’s my hope the ’22 election will be a referendum on the performance of the current administration, not a rehash of suggestions about what may have happened in 2020," McConnell emphasized.

The endorsements by McConnell and Thune come a week after Walker pushed back against Trump’s recent comments that Republican voters may sit out the 2022 and 2024 elections if the former president’s 2020 election claims aren’t addressed. 

"That is not the right message. Everyone has to get out and vote and we can’t look at the past," Walker said a week ago in an interview on Fox News Radio’s "Brian Kilmeade Show."