The race to fill Lindsey Graham’s seat has created a new test of President Donald Trump’s power. South Carolina Republicans aren’t sure Trump will pass.

Sen. Darline Graham, who was appointed last week to fill the remainder of her late brother’s term, announced Monday she will seek a full term for her brother’s old seat. Her decision came after winning Trump’s backing, and his endorsement of the political newcomer had the potential to scare away challengers.

But other Republicans are still charging forward, seeing an opening in a race with a highly untested candidate. Their determination is a signal that challenging a Trump-backed candidate may no longer be the career-ender it once was within the party.

“Even folks that didn’t like Senator [Lindsey] Graham or didn’t vote for him in the primary were pretty happy about the appointment, as a tribute to Senator Graham,” said CJ Westfall, chair of the Dorchester County GOP. “But once we saw the president jump in and support her, 95 percent are saying, ‘What the hell are we doing here? We don’t know how she votes. We don’t know what she believes.’”

“People that were excited about the appointment are now skeptical of the endorsement,” Westfall said.

Rep. Russell Fry, one of Trump’s most loyal congressional allies, announced earlier Monday he was jumping in. He joins Rep. Ralph Norman, who declared his own candidacy over the weekend, along with self-funding businessman Mark Lynch, who lost to the former senator in the primary. A number of other Republicans are mulling runs as well, including former Gov. Mark Sanford and Lt. Gov Pam Evette, who lost her own bid for governor a few weeks ago in spite of Trump’s endorsement.

While Trump’s endorsees have largely won their primaries, Evette’s recent loss isn’t his only setback. His picks lost in the Iowa and Georgia gubernatorial races.

“I think people saw [Trump’s] endorsement of Pam Evette and her terrible performance and know this race could be up for grabs like the gubernatorial was,” said a Republican operative unaffiliated with race who was granted anonymity to candidly discuss the landscape.

While Graham’s candidacy will test the power of Trump’s direct endorsement, there’s no question the MAGA movement is still the dominant force in South Carolina politics: All Republicans in the race are running as unapologetic supporters of the president, competing among themselves to prove who is the most authentic champion of Trump’s agenda — a dynamic that has defined GOP primaries across the country this year.

Norman told reporters on Monday that Trump’s endorsement “helps a great deal.” “That’s why I ask[ed] him for it,” he added. “I’d rather have it, but it’s up to the people.”

In Fry’s launch video, he presented himself as a Trump-aligned “MAGA warrior” — and included pictures of him grinning alongside the president.

In a statement, Fry campaign spokesperson Luke Byars noted Fry has “been honored to receive President Trump’s endorsement” in his previous elections.

“Our focus for the next three weeks remains ensuring South Carolina has a conservative fighter in the United States Senate who will advance the President’s agenda and deliver real results for South Carolina families,” Byars said.

Some Republicans said Graham’s lack of prior elected experience and the original expectation that she would only serve the remainder of her brother’s term have kept the field open.

“There is a desire to avoid yet another bruising Republican primary, right after we had a pretty contentious one for governor,” said Joel Sawyer, a longtime GOP strategist in South Carolina who’s not involved in the race. “But I don’t think that’s going to be the case.”

Trump’s endorsement of Graham gives her instant credibility despite her lack of electoral experience. But her campaign announcement on Monday was met with surprise and confusion by many across the state.

Most saw her appointment as a respectful gesture to the Graham family, and she was expected to be a caretaker who would hold the seat until the end of her brother’s term in January. Her interest in running for a full term even caught South Carolina party brass off-guard: Drew McKissick, chair of the South Carolina Republican Party, told POLITICO Friday he thought Graham told Gov. Henry McMaster she’d “accept the appointment to fill the rest of the term, not to be a candidate for it.”

A South Carolina GOP rule adopted earlier this year requires candidates for office to have voted in at least two of the past three statewide GOP primaries.According to local political outlet FITSNews, Graham voted in the 2024 GOP runoff but neither the 2022 nor 2024 GOP primaries. Whether Graham qualifies depends on whether, alongside her vote last month, her 2024 runoff vote counts as a primary vote under the new rule. The Dorchester County Republican Party announced it was formally requesting the state party’s rules committee review Graham’s eligibility.

McKissick, the state party chair, said Monday he hadn’t taken a look at the issue yet since the filing window doesn’t open until midday Tuesday, so no one had officially filed to run.

“As a result I haven’t seen information from any candidates yet,” he told POLITICO. “But suffice it to say that we will look at all of the various candidates’ information and official voting records from the state election commission when they do.”

A spokesperson for Graham’s campaign said she meets the state GOP’s primary voting requirement to file as a Senate candidate and is “qualified to run because she has real experience leading.”

“As to why she is running, it’s quite simple: she is a strong conservative who wants to build upon her brother’s legacy. There were never any conversations surrounding her appointment that were contingent upon serving only the remainder of Senator Lindsey Graham’s term,” Abby Zilch, a spokesperson for Graham’s campaign, said in a statement.

Trump’s endorsement power has been decisive across contested Republican primaries over the last several months, repeatedly propelling his favored candidate across the finish line. But his track record in South Carolina is murkier. After backing Evette early in the gubernatorial race only to see her struggle in the runoff, Trump offered a last-minute dual-endorsement to also back Attorney General Alan Wilson. Wilson ultimately beat Evette in the runoff by more than 30 points.

“I think it’s a nice sentiment,” said another GOP strategist of Trump’s endorsement granted anonymity to speak openly. “But at the end of the day she has no record, nor a right to the seat all because her brother held it. This is up to the people of South Carolina to decide.”

On Capitol Hill, Senate Majority Leader John Thune said he would stay out of the August 11 special election. Thune, who was close friends with Lindsey Graham, called his sister a “strong candidate” but said “I’ll let voters in South Carolina decide it.”

Other senators are diving in. Sens. Mike Lee (R-Utah) and Rick Scott (R-Florida), staunch allies of the president, announced their support for Norman over the weekend, publicly bucking Trump to back one of the House’s most conservative members. Both Lee and Scott specifically cited Norman’s support for the Save America Act, the election reform bill that has been a central focus for Trump in recent months. Norman also earned the nod of Turning Point Action.

Meanwhile, Norman — who passed on another term in the House to make an unsuccessful run for governor — has suggested Fry, his House colleague, could jeopardize Republicans’ House majority. If Fry wins the special election for Graham’s seat, the state would have to call a special election to fill his House seat, potentially leaving it empty for months.

“I respect Russell Fry and I have enjoyed serving with him in the House, but the reality is, his candidacy could leave his seat vacant until May 18th,” Norman wrote Monday.

GOP Rep. Nancy Mace announced Monday she would not enter the race.

The candidate filing window closes on July 28. Election Day is just two weeks later. The breakneck speed could play to Graham’s favor: She has the benefit of her brother’s campaign apparatus, which mobilized to win a primary outright last month while many of the state’s other contested races went to runoffs. And the memorial services for Lindsey Graham — scheduled for July 28 in Washington and July 29 in South Carolina — will shrink the calendar further.

“We say it’s a three-week campaign, but really it’s a two-week campaign after the funeral,” said Tyson Grinstead, an RNC committeeman and Richland County GOP chair. “I’m sure there’ll be ads and stuff, but it’s going to be hard for everybody to focus on campaign rallies and make a decision on this, in terms of voters, until after the funeral.”

If no candidate reaches 50% of the vote, a runoff election would be held in late August.

“We don’t always understand what’s going on in D.C.,” said Jeff Green, the GOP chair in Greenville County. “We try to give the president a lot of grace on these things. Would I have picked, you know, another Graham to replace Lindsey Graham? Probably not.”

“We don’t know her yet,” Green added. “But we’re open and trusting in what the president and his team are doing.”

Katherine Tully-McManus contributed to this report.