DANIEL ISLAND, S.C. — Rep. Nancy Mace is no stranger to an intraparty battle. Now, her role in a big Republican fight last year — the ouster of Kevin McCarthy as House speaker — is complicating her primary on Tuesday.

Mace, who is both a candidate seeking her third term and her own campaign manager, has earned the ire of the highest ranks of Republicans in the few short years she’s been in Washington. In 2022, it was former President Donald Trump — though they’ve since patched things up. Then, a year later, she voted in historic fashion to boot a House speaker from her own party.

In fact, McCarthy is the first thing Mace points to when asked about the stakes of her latest political fight against a primary challenger running with McCarthy’s support.

“It’s about revenge,” Mace told NBC News in an interview at her Daniel Island campaign headquarters. “It’s also about honesty and integrity. And my vote to oust Kevin McCarthy was about trust.”

Mace says she doesn’t regret the vote.

McCarthy, for his part, has said his support of GOP candidates challenging several of “the crazy eight,” as he calls the Republicans who voted against him, has nothing to do with political vendetta. Sources close to McCarthy point out he’s limited in what he can do directly, outside of giving money and advice. His spokesperson ignored a request for an interview.

But operatives aligned with McCarthy are directing big money into these races through outside groups. Tuesday’s challenge to Mace is the first test, followed by House Freedom Caucus chair Bob Good’s primary in Virginia next week. Two other anti-McCarthy voters — Reps. Eli Crane of Arizona and Matt Gaetz of Florida — are also facing primary challengers this summer.

In South Carolina’s 1st Congressional District, Catherine Templeton said Mace’s vote against McCarthy was “absolutely” what sparked her to run against Mace. Templeton is also a Trump backer and served as labor secretary in then-South Carolina Gov. Nikki Haley’s Cabinet.

Before launching her bid, Templeton met with Brian O. Walsh, a GOP political strategist and McCarthy ally. But she told The Post and Courier newspaper that she has not talked to McCarthy “about taking out Congresswoman Mace, but I have asked him to help raise money.” McCarthy contributed to Templeton’s campaign through his leadership PAC.

Yet Templeton also downplayed the former speaker’s role here, speaking between campaign stops in Beaufort.

“Her antics have consequences,” Templeton said of Mace, defining the race as larger than one action, though clearly tied to that historic vote. “All due respect to Kevin McCarthy, who is, I’m sure, a wonderful man: Nobody’s paying attention to Kevin McCarthy in the Low Country of South Carolina.”

What might catch voters’ attention, though, are the ads.

Three outside groups tied to McCarthy allies — American Prosperity Alliance, South Carolina Patriots PAC and Lowcountry Conservatives — have spent more than $4 million on ads against Mace alone, according to AdImpact, an ad tracking firm. The congresswoman has also had her own outside cavalry, too, though. The Club for Growth Action and one of its aligned groups have spent $3 million on ads to boost Mace.

Despite the barrage of outside attacks, and the negative attention the McCarthy vote brought here, there are upsides for Mace’s campaign. She has Trump’s endorsement, after she returned to the fold following criticism of Trump in the aftermath of the Jan. 6, 2021, Capitol riot.

She told NBC News “it was an easy call supporting Donald Trump” in 2024 “because we’ve had four years of Joe Biden”— a 180-degree turn from her statement that the GOP should move on from Trump following the Capitol attack.

And though the speaker vote didn’t earn her friends in D.C., it could play into her appeal with primary voters at home.

“Part of the reason that she’s being challenged right now is she challenged the system,” said South Carolina GOP strategist Dave Wilson, who is not involved in the race. “So it does kind of play into the narrative of, ‘Hey, listen, if you want to find somebody who’s willing to buck the system when they need to, Donald Trump and Nancy Mace are both willing to do that.’”

The handful of Republicans facing challenges at home talk sometimes about the McCarthy aspect, Mace allowed. “But I’m a caucus of one,” she said. “I don’t report to anybody in Washington. I don’t work for anyone. I work for South Carolina.”

She fended off a Trump-backed primary challenger in 2022. This time, “60-40” signs taped to the walls at her campaign headquarters illustrate her hope of quieting naysayers by earning far more than the 50% needed to win the GOP primary outright and avoid a runoff. A third candidate, Marine veteran Bill Young, is running in the GOP primary, meaning a runoff is possible.

“Everybody sort of leaves me for dead, right?” Mace said, reflecting on the ways her own party has come at her. “They say, ‘she’s out’ every election. It’s always, ‘she’s never gonna make it,’ and then we do. I want to win bigger than ever before Tuesday night because I want to send a message to Washington that voters don’t care about D.C.”

Ali Vitali and Kyle Stewart reported from Daniel Island, and Bridget Bowman from Washington, D.C.

This article was originally published on NBCNews.com