Knives out for Haley
What happens when someone rises in the polls? They attract attacks from their opponents. Both DeSantis and Ramaswamy have gone after Haley from the get-go in this debate, putting Haley on the defensive. This isn't really a shock, though, because Haley's poll numbers have been on an upward trajectory, both nationally and in the early states. She also just earned a major endorsement from Americans for Prosperity, a conservative advocacy group, which Haley mentioned when answering about her electability.
Past presidential primary debates have numerous examples of rising candidates facing attacks, but a famous debate from the 2016 Republican nomination race nicely showcases this. Florida Sen. Marco Rubio finished a strong third in the Iowa caucuses, and his campaign looked positioned to potentially compete for another solid finish in New Hampshire. But in the debate just ahead of that primary, Christie hit Rubio hard, most notably when he homed in on a moment when Rubio seemed to repeat a canned line multiple times and started calling the Floridian "Robot Rubio." Rubio finished fifth in New Hampshire and never recovered.
--Analysis by Geoffrey Skelley, 538