At several points during the second hour of the debate, it got particularly heated between former South Carolina Gov. Nikki Haley and someone she appointed to the U.S. Senate in 2013: Tim Scott.

Haley first went after Scott for not completing what he touted as his economic policy accomplishments.

“I appreciate him. We've known each other a long time. But he's been there 12 years and he hasn't done any of that. He has, they've only given four audits on time,” she said.

Then came a heated back-and-forth before Haley repeated, “Twelve years, where have you been? ... Bring it, Tim.”

The two also fought over Haley’s gas tax in South Carolina.

“​​I would love to finish my conversation with Nikki as it relates to the job that needs to get done. Nikki offered a 10-cent gas tax increase in South Carolina. Talk about someone who has never seen a federal dollar,” Scott said.

Haley then told Scott to do his homework regarding the spending and gas tax in South Carolina. He responded, “just go to YouTube.”

Haley ended the exchange by telling Scott that he was “scrapping right now” (as in scrambling).

“You are scrapping right now, you are scrapping. You know, I fought taxes, I cut taxes, I took care of South Carolina and you know it.”

They then got into a rift over a set of over $50,000 customized curtains for the State Department in the official residence of the ambassador to the United Nations. Haley was the first to live in the new residence.

–ABC News’ Abby Cruz, Gabriella Abdul-Hakim and Isabella Murray

After the moderator asked who should drop out of the GOP race, Christie said he'd have Trump drop out of the race if he had his pick because the former president has been so divisive. Ramaswamy offered an alternate view, arguing that Trump had been a great president, but that the America First movement isn't about one person but about "you," the American people. Once again, Christie differentiated himself by openly hitting Trump, something most of the other candidates shied away from tonight.

— Analysis by Geoffrey Skelley of 538

After last month’s debate, we declared Haley as a big debate winner, according to our previous poll with The Washington Post and Ipsos. When likely Republican primary voters who watched the debate were asked whether they’d consider voting for each candidate, Haley jumped from 30 percent before the debate to 47 percent after. Overall, participation in the debate was beneficial for candidates, and absence from the debate was (at least marginally) detrimental.

We’ll be following up with the same group as our pre-debate poll to see how participants performed and what respondents' views on all of the candidates are. Check back in with 538 tomorrow afternoon for our post-debate analysis.

—Analysis by Holly Fuong of 538

DeSantis gets another chance to be the adult in the room by rejecting the premise of that moderator question. He did the same thing in the first debate when the moderators asked candidates to raise their hands if they believed in man-made climate change.
-Jacob Rubashkin, 538 contributor

I’m monitoring Pence tonight, and I’ve got to be honest: I don’t know how much he can do to increase his standing in the primary other than hope that other candidates implode. During the last debate, he had plenty of speaking time and, given Trump’s hatred for his former vice president, a pretty strong reception from the Fox News crowd. But still, nothing substantially changed. Voters expected him to give an average performance, and he pretty much delivered. He’s averaging less than 5 percent in national primary polling.

It’s not clear where Pence has room to grow. He’s better known than any candidate on tonight’s debate stage, and voters seem to have decided how they feel about him. If he’s a second-choice to similar candidates — others who, say, share his dislike of Trump but would nonetheless support him in a general election — Pence could benefit from a smaller field. So, the best thing Pence could do might just be to stay the course, continuing to get enough support to appear on a debate stage and waiting out lesser-known and underfunded candidates.

—Analysis by Leah Askarinam