Christie criticized the idea that the president could cozy up to Vladimir Putin, noting that all recent presidents have failed to engage Putin by not being tough enough. He then hit Trump for having said that Putin was "brilliant and a great leader." As the night has worn on, Christie continues to be really the only candidate who is bothering to attack the guy who is 40 or more points ahead of every other candidate in national GOP primary polls.

— Analysis by Geoffrey Skelley of 538

Ilia Calderón is asking about sending U.S. troops to Mexico. In a late August/early September survey by Morning Consult, 41 percent of Republicans said they thought that sending U.S. troops to fight cartels in Mexico would be “very effective” at limiting the supply of illegal drugs in the United States. Other strategies had more support among Republicans, such as sending more resources to the U.S.-Mexico border (54 percent), empowering U.S. law enforcement to combat opioids (45 percent), and punishing drug violators in the United States (43 percent).
—Analysis by 538

Haley going after Ramaswamy was a recurring theme in the first debate. They were the standout candidates in our polling last time and there was a lot of speculation about Ramaswamy moving up in the polls — perhaps even surpassing DeSantis. But since August, Ramaswamy has actually lost support, to the point where Haley passed him in our polling average today. It makes sense that they're trading blows again; this seems to be a successful strategy for Haley, and Ramaswamy can't help but take the bait.
-Analysis by G. Elliott Morris of 538

The candidates are discussing support for Ukraine. About half (49 percent) of Republicans and Republican-leaning independents say that vital U.S. interests are not really at stake in the war in Ukraine, according to an August Echelon Insights survey. Thirty-seven percent disagree, saying that if Russia wins, vital U.S. interests and values are threatened. Fourteen percent are unsure.
—Analysis by 538

Hello readers! I’m Jacob Rubashkin (not 1992 VP candidate James Stockdale), and I’m a reporter and analyst for Inside Elections, a small, nonpartisan newsletter that does in-depth coverage of House, Senate, gubernatorial and presidential races. You may have seen our “race ratings,” which we publish regularly to assess each party’s chance of winning every election around the country.

Tonight, I’ll be reporting for duty as a 538 contributor, as I’ve done for many debates, primaries, and general elections over the past two years. I’ll be providing live analysis on the events playing out on stage, and also thinking about how the course of the GOP presidential primary will affect the fight for Congress next year, when Republicans aim to win back full control of Washington, D.C. (The debate is taking place in California’s 26th District, which is Solid Democratic, but right next door is the highly competitive 27th District, where vulnerable GOP Rep. Mike Garcia might not appreciate having to run with Trump at the top of the ticket).

—Analysis by Jacob Rubashkin, 538 Contributor