More race projections are coming in mere minutes after polls closed at 7 p.m. The Associated Press has already called the race for Trump based on their polling of voters, which showed Trump with a sizable enough lead to make the call. That call was echoed by other news organizations, including the New York Times, Wall Street Journal, and MSNBC. ABC News also projected Trump as the winner right as polls closed.

—Kaleigh Rogers, 538

I tend to agree with you, Geoffrey. Haley is presenting a very different kind of agenda and policy positions than the more MAGA side of the Republican Party. And voters are noticing the difference.

In polling from YouGov/CBS News in February, likely South Carolina GOP primary voters were asked how they thought each candidate’s policies would impact the country if they were to win the presidency. Seventy-three percent said Trump’s policies would make them financially better off, while only 32 percent said the same of Haley. On immigration, 88 percent of voters said that Trump’s policies would make the U.S.-Mexico border more secure, compared to 53 percent who said the same of Haley’s policies.

The contrast is particularly stark on foreign policy: When asked how Haley’s policies would impact U.S. military involvement overseas, 41 percent said she would increase, 44 percent said she would not change and 15 percent said she would decrease military involvement. The reverse was true of what voters expected from Trump: a plurality of 47 percent thought Trump’s policies would decrease U.S. military involvement overseas, while 20 and 33 percent expected his policies to not change or to increase involvement, respectively.

So I’d buy an argument that Haley may be staying in to keep a more hawkish foreign policy position alive in the party, which makes sense, given her history as U.N. Ambassador.

—Mary Radcliffe, 538

To Julia's point, up until now Haley has seemed like a classic "office-seeker" candidate — that is, someone running to win. Those kinds of candidates usually drop out once it becomes clear that they cannot win and that remaining in the race could damage them politically. However, there are also "agenda-seeker" candidates who are running to potentially promote a political agenda of some kind. If Haley is looking at the Republican Party and saying, "I probably don't have much of a future in a Trumpian GOP," perhaps — perhaps — she's looking to stay in the race to push back against the Trumpian direction of the party. To be clear, this is always a losing proposition in the near term. But agenda-seeking candidates often want to stay in the race as long as possible to broadcast their larger political agenda as long as they can.

—Geoffrey Skelley, 538

The questions about Haley dropping out touch on some bigger issues in the contemporary nomination process. The unwritten rules of the game matter a lot in presidential nomination politics, and in the past, a candidate like Haley — like John McCain in 2000 or Mitt Romney in 2008 — might stay in the race long enough to establish themselves as a viable candidate for a future race. But there’s also pressure for a candidate who clearly won’t win to suspend their campaign and unify the party. Trump’s unusual political trajectory has scrambled these unwritten rules of the game, however. Haley has said she won’t "kiss the ring", but there will be a lot of talk about whether she should leave the race, as the other competitors have. This depends not only on how the informal rules of the game work, but also on what Haley’s goals are. If she’s mostly setting her sights on 2028, then we might expect her to wind her candidacy down soon, in order to regain some standing among an increasingly Trump-loyal GOP. But her comments this week suggest that she’s running to push back on Trump’s dominance in the party, and perhaps to make the point that a political party is still just that: not only a movement focused on a single individual.

—Julia Azari, 538 contributor

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