Ramaswamy and Haley traded shots on his Israel and Russia-Ukraine views, with Ramaswamy interrupting Haley and claiming she has been saying misleading things about his proposals on Israel. Ramaswamy has called for winding down aid to Israel after integrating the country more into the region.

"I wish you well on your future career on the boards of Lockheed and Raytheon,” Ramaswamy quipped, referring to the aerospace and defense companies.

Haley struck back: "You have no foreign policy experience and it shows," she said -- and was met with cheers and applause from the audience.

-ABC News’ Abby Cruz

Trump wasted no time attacking other Republican candidates during his pre-taped interview with former Fox News host Carlson.

"I'm saying, do I sit there for an hour or two hours, whatever it's going to be and get harassed by people that shouldn't even be running for president?" Trump said.

The 46-minute interview -- released on Carlson's X account as the GOP debate got underway -- is being seen among the campaigns as an attempt to counter-program the first debate among 2024 Republican presidential candidates on Fox News.

Read more about the interview here.

-ABC News' Lalee Ibssa , Soo Rin Kim and Meredith Deliso

DeSantis expressed support for using the U.S. military to combat drug cartels across the border.

"The president of the United States has to use all available powers as commander in chief to protect our country and the people," DeSantis said.

"When they are coming across, yes we are going to use lethal force," he continued -- a line he's used repeatedly throughout the campaign.

Activists have pushed back that his plan is inhumane and illegal.

-ABC News' Alexandra Hutzler

Martha MacCallum just asked about what to do about migrants already in the United States. 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 FiveThirtyEight

This debate might be going out to a national audience, but the 2024 Republican presidential primary will be decided on a state-by-state basis — and because they’re the first to vote, Iowa, New Hampshire, South Carolina and Nevada will have an outsized impact on the race.

We’ve been collecting data on how many times each candidate has visited each early state, and there are some revealing trends. For one thing, the candidates seem to think Iowa and New Hampshire are much more important than South Carolina and Nevada. They’ve visited the first two more than 90 times each but South Carolina only 30 times and Nevada only four times. In addition, some candidates seem to be putting all their eggs in either New Hampshire’s or Iowa’s basket. For example, Christie and Hurd are focusing almost exclusively on New Hampshire — perhaps the famously independent Granite State will prove more receptive to their anti-Trump brand. Hutchinson, meanwhile, is focusing on Iowa.

Overall, Ramaswamy and Haley have paid the most visits to early states — though that’s partly because they announced their campaigns earlier than most other candidates.

-Analysis by Nathaniel Rakich of FiveThirtyEight