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

The Republican presidential primary started out in territory pretty friendly to Haley. That changes after today, making the South Carolina primary a sort of last chance for the former Palmetto State governor to prove she actually has a path to the 1,215 delegates necessary to secure the GOP nomination. It looks somewhere between unlikely and impossible that she'll be able to pull that off.

It's all about the numbers. According to the polls, Trump leads Haley by about 30 points among likely Republican primary voters. But his delegate lead is what really matters — and it's likely to be even larger. That's because the South Carolina Republican Party awards its delegates on a winner-takes-all basis. About half the delegates will go to the winner of the statewide vote (almost certainly Trump) and the remainder will go to the winner of each of the state's seven congressional districts. With a 30-point statewide victory, Trump would probably win every district resoundingly; in 2016, the largest difference between Trump's statewide margin (10 points) and his margin in the most anti-Trump county (which he lost by 5 points to Marco Rubio) was only 15 points.

This is all disastrous news for Haley, who needs all 50 delegates from the state to be on track to win the Republican nomination. The competition on and after Super Tuesday will be even tougher. According to the math powering 538's delegate benchmarks, Trump is leading Haley by around 57 points in California and 69 in Texas, the states with the largest delegate hauls on Super Tuesday. Those states also allocate delegates on a winner-takes-all basis, as long as a candidate wins at least 50 percent of the vote.

The primary, in other words, is functionally over. But because Trump has not yet clinched a majority of delegates, Haley's campaign technically has a chance of winning. It's just very, very low.

—G. Elliott Morris, 538