Nikki Haley shook hands with each of her GOP rivals, except Vivek Ramaswamy, after a fiery third Republican debate resulted in the two candidates clashing on stage.
Ms Haley appeared to snub the controversial pharma CEO, after Ramaswamy criticized her daughter's use of TikTok.
He quipped she should "take care" of her family first before speaking on the topic, to boos from the audience.
Visibly enraged, Haley fired back: “Keep my daughter’s name out your voice”
"You're just scum", she muttered.
Addressing Mr Ramaswamy’s performance after the event, Ms Haley said he would make America “less safe” if he won the presidency.