Donald Trump has picked up another endorsement from Nikki Haley's home state of South Carolina, with Rep. Nancy Mace backing the former president in this year's GOP presidential primary.

What You Need To Know

  • South Carolina Rep. Nancy Mace endorsed former President Donald Trump over former U.N. ambassador Nikki Haley one day before the New Hampshire primary

  • New Hampshire votes on Tuesday, but South Carolina's primary is in a month, and the state's Republican leadership has largely already lined up behind Trump

  • Haley, the former governor of South Carolina, lives in Mace’s district and supported her in 2022 against a Trump-backed challenger

Mace had stayed out of the 2024 Republican primary as two fellow South Carolinians — former Gov. Haley and Sen. Tim Scott — entered the race last year. On Monday, a day ahead of the New Hampshire primary, Mace told The Associated Press that she was backing Trump over Haley, who lives in her congressional district and supported her in 2022 against a Trump-backed challenger.

"I don't see eye to eye perfectly with any candidate. And until now I've stayed out of it," Mace said. "But the time has come to unite behind our nominee."

The South Carolina Republican's backing comes as Trump angles to bolster his dominance thus far in Republican balloting, following his record-setting win last week in the Iowa caucuses. Over the weekend, Trump was joined by a slew of South Carolina leaders as he campaigned in New Hampshire, seen as yet another blow from South Carolina against Haley.

Florida Gov. Ron DeSantis' departure from the race on Sunday leaves Haley as the main GOP candidate remaining to challenge Trump.

New Hampshire votes on Tuesday, but South Carolina's primary is in a month, and the state's Republican leadership has largely already lined up behind Trump. Mace's endorsement means that Trump has secured four of the state's six Republican U.S. House members, with Reps. Russell Fry, Joe Wilson and William Timmons also behind him, while Rep. Ralph Norman is backing Haley and Rep. Jeff Duncan is saying he's not endorsing before the primary.

Just two years ago, Mace and Haley were aligned in a congressional primary that tested Trump's heft in South Carolina, where his own 2016 presidential primary win helped cement his nomination.

After the Jan. 6, 2021, attack on the U.S. Capitol, Mace — who had just been sworn in as a freshman lawmaker — went on TV to criticize Trump for his role in the day's events, saying the president's accomplishments in office "were wiped out in just a few short hours." Trump had been trying to overturn the 2020 presidential election after he lost to Democrat Joe Biden and in a rally encouraged his backers to storm the Capitol, telling them they needed to "fight like hell."

Trump responded by calling Mace "an absolutely terrible candidate" and soliciting "any interest from good and SMART America First Republican Patriots" to run against a list of sitting House Republicans, including Mace, whom he endorsed for her first run in 2020 and who worked for his 2016 campaign.

When Katie Arrington, who unsuccessfully sought the seat in 2018, launched her 2022 bid against Mace, she had Trump's "Complete and Total Endorsement." During a pre-primary rally in South Carolina, Trump called Mace "crazy" and "a terrible person."

Haley, meanwhile, stumped with Mace, as she had in 2020, helping raise money and appearing in a television ad on her behalf, calling her a "fighter."

But the two haven't spoken since last year, when Mace's name was floated as a possible running mate pick for Trump, should he win the GOP nomination.

On Monday, Mace said she felt Trump was the better option this year.

"Donald Trump's record in his first term should tell every America how vital it is he be returned to office," she said.