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

It's not a huge surprise that Haley thinks she can win tonight despite the odds. Her first political success was in a 2004 South Carolina state House Republican primary, in which she unseated a powerful 30-year incumbent to win. She tells that story on the stump, and the message is clear: She's won as an underdog before.

As a legislator, Haley carved out a reputation in South Carolina as an outsider taking on state power. She sponsored a bill to force roll call votes on issues like raising legislator pay, losing support from her colleagues and a race for a committee chair position in the process. Later, as governor, she became known for luring businesses to the state, siding with business over labor, signing a 20-week abortion ban and blocking Medicaid expansion.

On social issues, though, she has tried to walk a middle path. Haley has talked about the racism her Indian American family faced in rural South Carolina, and supporters have said the "good ol' boys" network never quite accepted her in state politics. But she also frames her success as an example of how the South has made progress. She didn't tackle the issue of the Confederate battle flag flying over the State House until after a racist shooting in Charleston in 2015, in which nine churchgoers were killed in Emanuel AME Church. She has also sidestepped more recent controversies, like anti-transgender bathroom laws.

Of course, all of her history in the state hasn't seemed to help her against Trump. In polls, she's winning only about a third of potential voters. She may be used to playing the role of David, but not all Goliaths fall in defeat.

—Monica Potts, 538