Mr. Trump’s earlier supporters have seized on Mr. DeSantis’s departure from the race to declare Mr. Trump the “presumptive nominee,” though only Iowa has voted so far. Mr. Trump already has the support of Speaker Mike Johnson and the majority of congressional Republicans. After Mr. Trump’s 30-point win in Iowa, Senator Ted Cruz of Texas joined the list of backers.
Three of Mr. Trump’s former 2024 rivals for president — Senator Tim Scott of South Carolina; Gov. Doug Burgum of North Dakota; and Vivek Ramaswamy, the biotech entrepreneur — have also lined up behind him. In a closing show of unity among the rest of the G.O.P. field, all three of those men will appear alongside Mr. Trump on Monday night at a rally in Laconia, N.H., according to officials with the Trump campaign.
Some of the recent endorsements have doubled as betrayals to Ms. Haley. Representative Nancy Mace of South Carolina, supported by Ms. Haley last year as she fought off a Trump-backed primary challenger aimed at booting her from Congress, announced Monday that she would endorse Mr. Trump. Mr. Scott is from Ms. Haley’s home state — and she appointed him to the Senate while she was governor of the state in 2012. (Senator Marco Rubio of Florida, whom Ms. Haley endorsed for president in 2016, backed Mr. Trump shortly before the Iowa caucuses.)
Ms. Haley, by comparison, is backed by Gov. Chris Sununu of New Hampshire, former Gov. Larry Hogan of Maryland and former Gov. Asa Hutchinson of Arkansas — all politicians who represent the more traditionally conservative wing of the party. Former Gov. Chris Christie of New Jersey, who ran the most ardent anti-Trump campaign and was once seen as a potential supporter of Ms. Haley, appears to have no plans to endorse in the race.
Ms. Haley, who has long cast herself as “underestimated” in her political career, is using Mr. Trump’s flood of endorsements to position herself as the political outsider, something once seen as appealing about Mr. Trump. In Franklin, N.H., on Monday, she cast herself as willing to take on the political establishment now rallying behind Mr. Trump and the news media she said was wrongfully portraying his victory as inevitable.