Jacob, I agree that Haley sounded a bit like a third-party candidate tonight, taking on both frontrunners. If any voters were hoping to avoid a Trump vs. Biden rematch, it seems increasingly clear that they won't get their wish. Haley is staying in and attacking both Biden and Trump as two versions of the same thing: old, out of touch and not ready to take the country into the future. She still hasn't fully attacked Trump for his role in Jan. 6 and the court cases against him, which might win her some points with the non-Republican electorate, and it hasn't worked for her so far to try to make the age case against him. I don't think any of this will work, but we'll also have to see how Super Tuesday unfolds, since she seems to be staying in.

—Monica Potts, 538

If Haley is contemplating a third party bid, she’d have a lot of ground to make up. We’ve seen only two polls testing Haley as an independent, and both show her in the low double digits: SurveyUSA/Charles H. Riggs III has her at 13 percent in a 3-way race against Trump and Biden, with Trump at 45 percent and Biden at 40 percent, and Emerson College has her at 12 percent, with Trump at 42 and Biden at 37. When you throw in Kennedy, West and Stein, she drops to 10 percent in that SurveyUSA poll.

So, if she really wanted to make a go of a third party bid, she’d have to hope something pretty dramatic happened to move voters in her direction. Otherwise, it looks like a third party bid would be DOA.

—Mary Radcliffe, 538

Haley spent a good portion of her speech attacking Trump and Biden in equal measure. It definitely raised the specter of a third-party candidacy down the line, after she loses the GOP nomination, perhaps on the No Labels ticket. Haley has said she’s “not interested in talking” with the centrist group, but that doesn’t mean she can’t develop an interest later on.

And it’s not entirely unheard of for a losing GOP candidate to launch a more center-minded independent bid for president against an incumbent Democrat and the Republican who beat them in the primary. Illinois Rep. John Anderson did just that in 1980 against Jimmy Carter and Ronald Reagan. He ultimately won about 6.6 percent of the vote (5,719,850 popular votes, but no electoral votes).

—Jacob Rubashkin, Inside Elections

That electability case may not be resonating with actual primary voters, though. According to a January poll conducted by Monmouth University/The Washington Post, likely South Carolina GOP primary voters care more about issues than electability in choosing their nominee. Sixty-two percent said it was more important to nominate a candidate whose positions on the issues are closest to their own, while 33 percent said it was more important to nominate a candidate who seems most likely to beat Biden in November. There was little difference between Trump and Haley voters on this: 61 percent of Trump voters and 64 percent of Haley voters said that issue positions were more important, while 34 percent of Trump voters and 31 percent of Haley voters chose electability.

—Mary Radcliffe, 538

I have become a little obsessed tonight about what we should be expecting Trump to hit in this primary a priori. That is, given Trump is assumed to be the eventual party nominee and almost universally liked in the GOP, should he be winning more than 60 percent in South Carolina?

I already gave my case for answering "no" to that question: Strictly speaking Trump is dominating the delegate count and running ahead of his 2016 vote share in most counties with complete counts this primary cycle. And if you consider that Haley gets a home-state advantage in South Carolina tonight, Trump's adjusted vote share is close to 65 or 70 percent; our delegate benchmarks think Trump should have won 68 percent of the vote based on the demographics of the state alone. That's not the highest number, but it's not the lowest right? Would 65 percent be "good" for Trump? 75 percent? 80?

One counterargument to this centers around how the media has covered historical performances by incumbent presidential candidates. Journalist Jill Lawrence points out that in 1992, Patrick Buchanan challenged incumbent President George H.W. Bush for the GOP nomination and won 40 percent in the New Hampshire primary, holding Bush to 58 percent of the vote. That's an almost identical split to the results from tonight. The New York Times journalist Robin Toner wrote up the results with the headline "BUSH JARRED IN FIRST PRIMARY" and said the result "amounted to a roar of anger" from Republican primary voters.

If Trump was a true incumbent, I imagine the news media would use a similar headline to describe tonight's results in South Carolina. Perhaps our expectations for him are too low, or we're too focused on the broader state of play? Haley said in her concession speech tonight that she will stay in the race indefinitely, so I guess we'll get more data on Super Tuesday — only 10 days from now. The primary lives on!

—G. Elliott Morris, 538