Ramaswamy, a pugnacious entrepreneur who delights in making outrageous statements, provoked groans from the audience during a discussion on banning TikTok when he mentioned that Haley's daughter had used the Chinese short video app.

"You might want to take care of your family first," he told Haley, a former U.S. ambassador to the United Nations and a former governor of South Carolina.

"Leave my daughter out of your voice," Haley shot back, adding under her breath, "You're just scum."

It was not the first time Haley, a foreign policy hawk, and Ramaswamy, an anti-interventionist on foreign conflicts, have clashed over TikTok. "Every time I hear you I feel a little bit dumber," Haley said after they crossed swords about the app during a previous encounter in September.

On social media platform X, Haley's son, Nalin Haley, said Ramaswamy's attack was "desperate," adding that his sister's TikTok account was deleted a "very very long time ago."

Haley is vying with Florida Governor Ron DeSantis to become the top challenger to runaway favorite Donald Trump in the Republican nominating contest. Ramaswamy, a relative unknown at the start of the year, gained buzz earlier this year but appears to have since lost momentum.

(Reporting by Alexandra Ulmer; Editing by Ross Colvin and Howard Goller)

By Alexandra Ulmer