Haley Assails Trump as ‘Unhinged’ and Dismisses Calls to Exit the Race

Nikki Haley on Friday called Donald J. Trump “totally unhinged” after a failed attempt by one of his allies to push the Republican National Committee to declare him the party’s presumptive nominee, escalating her attacks on his mental acuity.

Ms. Haley, the former South Carolina governor and Mr. Trump’s ambassador to the United Nations, cast her onetime boss as increasingly antagonistic during an appearance on Fox News.

“Let’s look at the last 48 hours,” Ms. Haley said, and she went on to assail him over his combative rhetoric in his victory speech Tuesday in New Hampshire.

“He throws an absolute temper tantrum, talking about revenge,” she said. “Then he goes and says that he’s going ban anyone from MAGA that donates to me.”

“I mean he’s totally unhinged,” she said.

She also accused him of being behind an R.N.C. member’s plan to use a resolution to try to force the party to say the nominating contest was effectively over. But the plan was withdrawn after Mr. Trump rejected it in a post on his Truth Social website.

Ms. Haley, who lost to Mr. Trump, the G.O.P. front-runner, by about 11 percentage points on Tuesday in the New Hampshire primary, has vowed that she will continue her uphill campaign.