Former U.N. ambassador Nikki Haley is facing growing pressure from fellow Republicans to drop out of the presidential race after placing second in the New Hampshire primary, with key GOP leaders urging the party to unite around a single candidate as quickly as possible.

After two nominating contests, Haley is the only major challenger to Donald Trump remaining in the Republican primary — with the former president garnering decisive wins Tuesday in New Hampshire and also in last week’s Iowa caucuses. Though Haley came closer to Trump in the Granite State than some pre-primary polling indicated, she faces an uphill battle in the next states to hold nominating contests. That slate includes her home state of South Carolina, where Trump maintains a commanding lead in the polls.

Ronna McDaniel, chairwoman of the Republican National Committee, told Fox News on Tuesday that she did not see “the math and the path going forward” for Haley to win the party’s nomination but stopped short of explicitly calling for Haley to drop out.

“I think she’s run a great campaign. But I do think there is a message that’s coming out from the voters, which is very clear: We need to unite around our eventual nominee, which is going to be Donald Trump, and we need to make sure we beat Joe Biden,” McDaniel said.

She noted that Haley had poured resources into New Hampshire and garnered the support of Gov. Chris Sununu (R) along with independent and unaffiliated voters in the state — and still came in second.

“I just think if she came in second here, I don’t see the path,” McDaniel said. “… This isn’t the RNC speaking. This isn’t the establishment speaking. This is the voters speaking.”

Haley has vowed to stay in the race for the long haul and has vehemently pushed back on the notions that she would drop out or be content with being named a vice-presidential candidate. At her New Hampshire watch party Tuesday night, Haley was upbeat, congratulating Trump on his projected win — saying “he earned it” — but also declaring that the race was “far from over.”

“There are dozens of states left to go. And the next one is my sweet state of South Carolina,” she told cheering supporters. “… I’m a fighter, and I’m scrappy. And now we’re the last one standing next to Donald Trump.”

Still, the pressure campaign from Trump’s supporters began as Haley gave her speech to supporters. Within 30 minutes, three Republican senators publicly signaled their desire to see Haley quit.

“I have seen enough,” Sen. John Cornyn (R-Tex.) wrote on X, formerly Twitter, at 8:05 p.m. “To beat Biden, Republicans need to unite around a single candidate, and it’s clear that President Trump is Republican voters’ choice.”

A few minutes later, Sen. J.D. Vance (R-Ohio) piled on. “At this point Haley can either drop out or help the Democrats,” he wrote on the platform.

Another 10 minutes later, Sen. Deb Fischer (R-Neb.), who had not previously backed a candidate in the primary, announced on X that she was endorsing Trump and that it was “time for the @GOP to unite” to defeat Biden.

Sen. Lindsey Graham (R), who is from Haley’s home state and who long ago backed Trump, joined his fellow Republicans’ call Tuesday night, writing on X: “The sooner we unite, the better.”

The chorus of Republicans publicly calling for the party to rally behind Trump only grew louder, with Sen. Eric Schmitt (Mo.), Rep. Dan Bishop (N.C.) and Rep. Harriet Hageman (Wyo.) all declaring the primary over in social media posts.

Haley, her campaign officials and top surrogates have all continued to express optimism for the nominating contests ahead, saying they did not want to see a Trump “coronation.” Haley spent Wednesday morning speaking to Republicans in the U.S. Virgin Islands, which will hold its caucuses on Feb. 8 to determine how to award its delegates.

Haley’s allies also pointed to her stronger-than-expected performance in Iowa, where she won eight delegates, and in New Hampshire, where she is projected to come within 11 percentage points of Trump, despite pre-primary polling showing that Trump had a 28-point lead. (The poll was conducted before Florida Gov. Ron DeSantis announced over the weekend that he was suspending his campaign.)

In a memo Tuesday outlining the state of the race, Haley campaign manager Betsy Ankney noted that South Carolina and Michigan each have open primaries, meaning anyone can vote in the GOP primary as long as they have not already voted in the Democratic one — a more welcoming landscape for Haley, who has fared better with independent and unaffiliated voters than Trump.

And on March 5, or Super Tuesday, 11 of the 16 states and territories will hold open or semi-open primaries, representing “significant fertile ground” for Haley, Ankney wrote.

“After Super Tuesday, we will have a very good picture of where this race stands,” Ankney added. “At that point, millions of Americans in 26 states and territories will have voted. Until then, everyone should take a deep breath.”

On Wednesday morning, Sununu, the governor who endorsed and campaigned alongside Haley in his home state, said the notion that Haley would drop out now was “nonsense.”

“With all due respect to Ronna McDaniel, to say that we’re just going to call it after two states, [with] 40 states to go … because it’s getting too close? That’s nonsense,” Sununu said on Fox News. “You got to let the voters decide, not a bunch of political elites out of D.C.”

Sen. Susan Collins (R-Maine) told reporters Wednesday that she was happy to hear that Haley was determined to stay in the race but acknowledged that she had not formally endorsed her.

“I think the more people see of her, particularly since she appears to be the only alternative to Donald Trump right now, the more impressed that they will be,” Collins said.

But a mounting concern for Haley, even if she does not want to leave the race, will be holding on to donors who said Wednesday that they worried about her chances in her home state of South Carolina.

Metal magnate Andy Sabin, who had previously donated the maximum amount to Sen. Tim Scott’s (R-S.C.) presidential campaign before Scott dropped out, had also donated a small amount to Haley. But Sabin, who previously said that Haley needed to win New Hampshire to pose a real challenge to Trump, said he would no longer contribute to her campaign.

Sabin, who has been vocally critical of Trump in the past, said he had resigned himself to supporting Trump by encouraging people to vote for the former president — but the Republican donor drew the line at financial support.

“I’m not going to give him a nickel, which I’ve said,” Sabin told The Washington Post. “But I’m going to do everything I can to get him elected.”

Multiple advisers to political megadonors, who spoke on the condition of anonymity to discuss private conversations, said they think significant future funding for Haley is unlikely after her New Hampshire performance.

“Without a New Hampshire win, she doesn’t have the momentum she needed to win South Carolina,” one adviser said. “And without a lane to South Carolina, she has no chance on Super Tuesday.”

But not everyone has given up on Haley. Eric Levine, a prominent Republican fundraiser, said he was continuing to raise money for her, despite the disappointment over Haley losing New Hampshire.

“As long as she’s in the race, I am with her,” he said.

Americans for Prosperity’s super PAC, the flagship group of the political network led by conservative billionaire Charles Koch that contributed its sophisticated ground operation and political networking power to Haley’s operation in Iowa and New Hampshire, said it plans to continue its work for Haley in South Carolina. The group noted the “steeper road ahead” in a statement released after the New Hampshire results were announced. But the organization has already contacted about 300,000 South Carolinians as of Wednesday, said spokesman Bill Riggs.

Mark Harris, the lead strategist of the pro-Haley super PAC SFA Fund, said he expects continued support — “people are jazzed up,” he said — but added that he knows that Haley, as “an insurgent candidate,” will be outspent.

“Our donors have been in this from the long haul,” he told reporters Wednesday. “They believe in Nikki Haley. They believe in a new direction for the country.”

Michael Scherer contributed to this report.