That's true, Nathaniel. But maybe Haley is hoping that actively campaigning, and still having a campaign apparatus running, will give her an advantage over the other also-rans.

—Monica Potts, 538

Remember that the primary is ultimately all about the delegates candidates win to vote for them at the RNC in July. In the delegate math tonight, Trump is coming out way ahead. South Carolina awards delegates in two sets: 29 are awarded to the winner of the statewide popular vote (which are all going to Trump tonight) and the remaining 21 are split equally between the remaining 7 congressional districts. According to ABC's delegate projections Trump has already won 38 delegates tonight, with 12 left to assign in 4 more districts. But if Trump is heading for a 30-point margin statewide, it's unlikely Haley will win any of those that remain.

Our delegate benchmarks model had Haley needing all 50 tonight to be on track for the GOP nomination. It is her home state, after all.

—G. Elliott Morris, 538

Am I the only one who uses the term "bet your bippy"??

—Nathaniel Rakich, 538

Right, so why is Haley sticking around if Trump is the presumptive nominee? We've put together a few hypotheses — spite, in case something happens, sticking it to the man etc — but, as ever with politicians, we cannot discount the possibility that she's in it for her. I keep thinking of Beto O'Rourke's "born to run" comments in the 2020 primary. A lot of politicians think this way!

—G. Elliott Morris, 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