Likely Republican voters are pretty split on "sending U.S. military forces to Mexico to fight drug cartels," according to our pre-debate 538/Washington Post/Ipsos poll. 44 percent support the proposed policy, compared with 46 percent who oppose.

—Analysis by Holly Fuong of 538

Some early moments in this debate have involved significant cross-talk and interruptions. Burgum's main two comments so far both came via him jumping in to speak without having been asked a question, which is something a low-polling candidate on the periphery of the stage (and race) might as well do with little to lose. Unlike in the first debate, there hasn't been as much of a push by the moderators to give a short rebuttal opportunity to candidates who were mentioned by another candidate, although multiple candidates have asked for that already.

—Analysis by Geoffrey Skelley of 538

The Trump administration built 52 miles of new primary border barriers — the first impediment people encounter if they’re trying to cross the southern border with Mexico, that can block access either for people on foot or for vehicles — where there were none before.

The administration built 458 total miles of primary and secondary border barriers, U.S. Customs and Border Protection data shows. The majority were replacements of smaller, dilapidated barriers.

The U.S.-Mexico border stretches for 2,000 miles across four states and a variety of terrain.
-Analysis by Aaron Sharockman, PolitiFact

Christie was just asked about his position on a pathway to citizenship for undocumented immigrants. In a July poll by The New York Times/Siena College, 39 percent of likely Republican voters say that they supported a “comprehensive immigration reform bill that provides a pathway to citizenship for all undocumented immigrants” in the United States, while 57 percent opposed such a bill. Support was weakest among Trump supporters (29 percent) compared with DeSantis supporters (48 percent) and voters who say they will vote for another candidate (50 percent).
—Analysis by 538

Foreign policy isn’t quite dominating this debate, but U.S. policy towards China is a prominent theme, and Ramaswamy is bearing down a lot of attacks on that.

Ramaswamy and Haley had a heated moment on the debate stage over the issue of support for Ukraine – which Haley tied to China. When Ramaswamy argued against support for Ukraine, Haley jumped in, saying that a win for Russia is a win for China, and then accused Ramaswamy of liking China.

There was also the memorable TikTok exchange between the two. Haley sniped at Ramaswamy that "every time I hear you, I feel a little bit dumber for what you say” and that he can't be trusted as he justified his choice to join TikTok after being convinced by influencer and boxer Jake Paul to join despite previously calling it "digital fentanyl." TikTok was created by Chinese company ByteDance and lawmakers have scrutinized the app over security concerns. (Ads for TikTok are also airing on Fox Business Network during commercial breaks.)

Scott also accused Ramaswamy of being ‘bought’ by China. He was likely referencing Ramaswamy's company, Roivant Sciences, announcing 5-years ago that it was partnering with China state-owned investment company CITIC Group Corp

And Pence had a similar, pointed attack: “I'm glad Vivek pulled out of his business deal in 2018 in China -- that must have been about the time you decided to start voting in presidential elections."

It’s worth noting that Haley criticized Trump too on this front, in that case for not pursuing China aggressively enough on a host of issues: “This is where President Trump went wrong.”

– ABC News’ Kendall Ross, Libby Cathey, Soorin Kim, Abby Cruz, Nicholas Kerr, and Oren Oppenheim