DeSantis wouldn’t directly answer when the moderators asked him if he would sign a national abortion ban, and Pence pounced. He comes from the social conservative wing of the party, and supports a national ban. This isn’t the first time Pence has criticized DeSantis for not being conservative enough on abortion, either.
-Analysis by Nathaniel Rakich of FiveThirtyEight

Haley reiterated her calls for "compassion" when the country debates abortion, though she declined to state whether she would support a federal ban on the procedure.

Haley noted the uphill climb to a federal ban, referencing the 60-vote filibuster in the Senate, but said she would oppose late-term abortions and punishments for women who receive abortions.

"Can't we all agree that we should ban late term abortions? Can't we all agree that we should encourage adoptions? Can't we all agree that doctors and nurses who don't believe in abortion shouldn't have to perform them? Can't we all agree that contraception should be available? And can't we all agree that we are not going to put a woman in jail or give her the death penalty if she gets an abortion? Let's treat this like the like the respectful issue that it is," she said.

-ABC News' Tal Axelrod

The candidates are now debating abortion, which has obviously been a hot-button issue lately, but it’s actually not super important to Republican primary voters right now. According to our FiveThirtyEight/Washington Post/Ipsos poll, only 6 percent of Republicans identified limiting abortion as one of their top three issues.
-Analysis by Nathaniel Rakich of FiveThirtyEight

In the commercial break we get an ad targeting pro-Ukraine Republicans from Defending Democracy Together, a PAC led by a group of anti-Trump conservatives who have been very active in politics since 2017. In a poll from the Pew Research Center in June 44 percent of Republicans said the US was giving too much aid to Ukraine. I'm not sure how much this ad is going to register; Ukraine and national defense barely register in polls of Americans' most important problem these days. I think it says more about the divide in the party over Trump — who hasn't been mentioned in the debate at all so far.
-Analysis by G Elliott Morris of FiveThirtyEight

The 2024 presidential election has been underway for months, but with tonight’s first Republican primary debate in Milwaukee, we’re kicking off a new phase of the campaign. In these final five months before voting begins, we’re going to have monthly debates, dashes through Iowa, big-money fundraisers — and probably a culling of the field.

Tonight’s debate will feature eight candidates. Front-runner Donald Trump, who has a 37-percentage-point lead in FiveThirtyEight’s national polling average, will not be among them, as he has opted to skip the debate. Instead, we will hear from Florida Gov. Ron DeSantis; entrepreneur Vivek Ramaswamy; former Vice President Mike Pence; Sen. Tim Scott; former U.N. Ambassador Nikki Haley; former Arkansas Gov. Asa Hutchinson; North Dakota Gov. Doug Burgum; and former New Jersey Gov. Chris Christie.

There are a few threads and tensions we’re going to be watching tonight. First, in the absence of Trump, will his challengers’ attempts to position themselves as a more favorable option fall flat? How will candidates make their case for being a better alternative to Trump without having the contrast on stage beside them? Secondly, what sort of friction will we see between the anti-Trump candidates and those running on more similar ideas or rhetoric?

We’ll keep an eye on all this and more. You’ll be hearing from the crew at FiveThirtyEight and ABC News — as well as some new friends at PolitiFact — throughout the night. The Fox News-hosted debate begins at 9 p.m. Eastern, and we have some colleagues on the ground in Milwaukee who will ensure you’re going in with everything you need to know.

Thanks for joining us. Stay tuned as we update the blog with real-time analysis, charts, thoughts, questions, ideas, idle fancies and more. Leading up until the debate starts, we’ll run through the state of the race so far. Once the debate starts, we’ll make sure we’re addressing everything happening on stage, including what issues the candidates talk about, who they attack, how they position themselves and what Americans think.

-Analysis by Maya Sweedler of FiveThirtyEight