GOP Rep. Nancy Mace lost her bid to move into South Carolina’s governor’s mansion because, in her words, she voted to release the Epstein files.

“And apparently, I chose wrong if the goal was winning an election,” she said in her concession speech.

After finishing fifth when the polls closed Tuesday night, the three-term representative said, “I voted to release the Epstein files and lost some support for that.”

She added, “As a survivor, I chose to stand on principle and stand against the Epstein cover-up. I chose to expose the names hidden in the sexual harassment slush fund. I chose to expose DEI judges. I chose to expose the abusers of children.”

Even though she believes it cost her the GOP primary nomination, she said she’s “at peace with that.”

“Because when a candidate is OK with corruption and cover-ups — something is broken,” she continued. “That’s not a political opinion. That’s a moral emergency.”

The discharge petition to force a vote on a bill to compel the Justice Department to release the Epstein files included four Republicans, one of whom was Ms. Mace. Ultimately, the Epstein Files Transparency Act passed the House with a 427-1 vote and the Senate by unanimous consent before President Trump gave his stamp of approval in November.

Amid her defeat, she didn’t allude to her outbursts caught on camera, mention her high-profile clashes with House GOP leadership and breaking with her party on policy issues, or cite her falling on the president’s bad side.

Mr. Trump remained largely absent from the race even as the Republican candidates campaigned in anticipation of his endorsement. He finally endorsed Lt. Gov. Pamela Evette in the final two weeks.

Ms. Mace did not expressly single out Mr. Trump for endorsing her opponent — unlike Sen. Bill Cassidy, Louisiana Republican, who lost his primary, thanks to the president’s fierce opposition. She did, however, endorse Attorney General Alan Wilson, who is heading to the June 23 runoff against Ms. Evette.

Why she didn’t receive the president’s support, Ms. Mace said, is her leading role in the Epstein case.

“That’s the sole reason I didn’t get the endorsement, because I voted to release the Epstein files, and I’m OK with that,” she told Politico in a preprimary interview. “I’ve worked very hard to expose pedophiles and child rapists and sex trafficking in my state and will continue to do it regardless of the outcome of the election.”

She also provoked the president by saying he had a role in the Jan. 6, 2021, riot at the U.S. Capitol. Mr. Trump endorsed former South Carolina Rep. Katie Arrington in the 2022 Republican primary against Ms. Mace, who emerged with 53% of the vote and ready to embrace the president again.

“Nancy fights Republicans all the time and is not at all nice about it,” Mr. Trump said before that primary. “Frankly, she is despised by almost everyone, and who needs that in Congress, or in the Republican Party?”

Years later, she still labeled herself “the MAGA candidate,” adding, “I support our president.”

As her tenure in the House is coming to a close, she said she’s closing the book on any future run.

“I’m not running for Congress again,” Ms. Mace told Politico. “I said I would do six years because I believe in term limits, and I made the promise that I would leave Congress after six years, so I won’t be running again.”

Instead, she said she’ll return to the private sector at the end of her term, “as the Founders intended.”

“When I ran in 2020, I said I’d only serve three terms and my time is up,” she said on social media. “It’s truly been an immense honor, and I wouldn’t trade it for anything else.”