Haley finally gets a question on foreign policy, a strong suit for the former U.N. Ambassador. She defends American support for Ukraine and ties it to the fight against China. But while the moderators teed her up to attack DeSantis, she instead pivots to Ramaswamy. She's pretty fiery in her back-and-forth with him, saying he has no foreign policy experience "and it shows."
-Analysis from Jacob Rubashkin, Inside Elections

On Russia's invasion of Ukraine, Christie referenced his recent trip to the war-torn country and said that he "wanted to see for myself what [Russian President] Vladimir Putin's army was doing to the free Ukrainian people."

"They have gouged out people's eyes, cut off their ears and shot people in the back of the head," Christie said of the brutality he saw.

"This is the Vladimir Putin who Donald Trump called 'brilliant' and a 'genius,'" he continued. "If we don't stand up against this type of autocratic killing, we will be next."

-ABC News' Meredith Deliso

Born in 1985 and only 38, Ramaswamy may be the only candidate on stage who was too young to remember the Cold War. The USSR dissolved when he was 6.
-Analysis by Monica Potts of FiveThirtyEight

The debate over Ukraine is a window into the intraparty battle between its previously more dominant neoconservative wing that lost credibility during and after the George W. Bush years and the comparably isolationist wing that's gained ground with Trump's time in office. Ramaswamy, as an avatar for the New Right, specifically name-checked the Iraq War, saying the Ukraine conflict could lead to American intervention. By comparison, Pence and Haley, more traditional conservatives who have foreign policy experience from their time as vice president and U.N. ambassador, respectively, were especially vocal in defending U.S. support for Ukraine.-Analysis by Geoffrey Skelley 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