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

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