Adding onto Nathaniel's Google search comment ... debates can serve as a great introduction to some of the lesser-known candidates. Ramaswamy is probably tonight’s big winner in making a name for himself: 59 percent of voters had no opinion or had never heard of Ramaswamy before tonight, according to a favorability question in our pre-debate FiveThirtyEight/Washington Post/Ipsos poll. That’s likely changed after all of the talking he’s done on stage — and we’ll be tracking whether that’s a good or bad thing. Check back in at FiveThirtyEight tomorrow afternoon for our post-debate analysis.
-Analysis by Holly Fuong of FiveThirtyEight

Pence was pressed by moderators if presidents should have to pass a mental and physical test to serve, invoking President Joe Biden's age.

Pence, who is 64, initially joked that "it might be a good idea to have everybody in Washington" pass one.

He then took a serious tone, saying, "No, the American people can make those judgments."

He appeared to take a swipe at Ramaswamy, the youngest candidate on stage, stating the nation doesn't need a president who is too young either.

-ABC News' Alexandra Hutzler

In the front-runner's absence, many of us here at FiveThirtyEight suspected (in part because of some leaked debate memos) that the former president would loom large over the proceedings, with candidates taking shots at him whenever possible. That hasn't really happened tonight, though! What do you make of it?

-Analysis by Maya Sweedler of FiveThirtyEight

Ramaswamy has been far and away the most Googled candidate during the debate tonight. He’s received three times as much search interest as DeSantis or Haley. Now, I’m not sure what that means for his chances — Google searches aren’t votes, and people might just be curious to learn more about him. But I think it does reflect that he has been the story of this debate so far. Whether that’s a good story for him or a bad story is still TBD.
-Analysis by Nathaniel Rakich 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