The moderators finally turn to discussing Trump, who has skipped the debate for a (pre-recorded!) interview with Tucker Carlson. It's clearly intentional that they waited this long — Trump is ahead by 37 points in our national polling average, so he's an obvious elephant (not) in the room. In some ways the entire debate is moot because of that lead. Remember that these candidates are running for second and third place right now, not first.

-Analysis by G Elliott Morris of FiveThirtyEight

Burgum has mentioned his small-town roots a few times during the debate, most recently to hold up small towns as an example of how to beat back rising crime. A lot of what distinguishes Burgum from the field -- his success as tech CEO, his more pragmatic politics, his low-key demeanor -- don't necessarily play well in today's Republican Party, but small-town politics is usually a winner. Just look at the success of Jason Aldean's "Try That In a Small Town" among conservatives earlier this month.
-Analysis by Jacob Rubashkin, Inside Elections

A group of more than 100 anti-Republican protestors temporarily took to the street outside Fiserv Forum after the debate began.

The group was advocating on behalf of several causes championed by the left, carrying signs advocating for abortion rights, transgender rights, immigrant rights and Black Lives Matter, among other causes.

Some of the signs were more explicitly political in nature, directly targeting GOP candidates.

One protestor carried a sign reading “Down with DeSantis.”

The group cheered, whistled and chanted as they advanced down the street.

“Get up, get down, Milwaukee is a union town,” was one chant that could be heard.

The protestors were accompanied by legal observers.

The group walked down an open street and at one point briefly blocked traffic. The protestors were otherwise peaceful and dissipated soon after they began.

-ABC News’ Allison Pecorin and Olivia Osteen

The candidates came to the debate prepared with answers about abortion – carefully considering their wording, and, in a stark departure from the first half hour, actually answering the moderators’ question on the issue.

One thing the candidates didn’t want to talk about? Climate change. The moderators asked the candidates to raise their hand if they believed human behavior was driving climate change — but that didn’t happen. Instead, DeSantis said he wanted to debate rather than answer a question like “school children.” Ramaswamy chimed in to say “the climate change agenda is a hoax,” drawing boos from the crowd, though it wasn’t clear what exactly they were booing. Christie jumped in to say that Ramaswamy sounded like both ChatGPT and Obama. Haley decided that this was the moment to quote Margaret Thatcher — “if you want something done ask a woman” — though she did answer that climate change was real, putting the onus on China. And Scott used the moment to chide the rest of the field for being “childish.”

— Analysis by Leah Askarinam of FiveThirtyEight

Recent election cycles have shown how debates can substantially alter a candidate’s trajectory. The debates won’t always do this, of course, and early primary polls remain relatively predictive of who will end up winning a party’s nomination. However, a candidate can earn a real polling bounce from a debate — or fall into a valley.

Primary polls are inherently more volatile than general election polls. In a general election, most voters already lean toward one party, so only a small part of the electorate is likely to shift its views over the course of a campaign. But in a primary, voters in one party may be open to multiple candidates because most contenders will share similar views on a number of issues. As a result, exposure to an unfamiliar candidate could prompt voters to begin considering that contender, while a strong or weak performance by a candidate they do know could make them look elsewhere.

For example, early in the 2012 cycle, Texas Gov. Rick Perry appeared to be now-Sen. Mitt Romney’s most serious opponent for the Republican nomination. But in a September 2011 debate, Perry defended a Texas policy that gave undocumented immigrants access to in-state college tuition. The backlash from the GOP base came swiftly, as Perry fell out of contention in the polls, well before a later debate in which he — oops — forgot the name of the third of three federal agencies that he aimed to dismantle as president. Four years later, former tech executive Carly Fiorina had very little support early in the 2016 Republican race, but in August 2015 she stood out in an “undercard” debate. Her polling numbers improved and she made the main stage in subsequent debates, giving her a platform that eventually led Texas Sen. Ted Cruz to make her his vice presidential pick in a last-ditch attempt to rally support against Trump in the 2016 primary.

-Analysis by Geoffrey Skelley of FiveThirtyEight