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

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