If voters are focused on immigration, as the preliminary exit polling shows, that almost certainly plays to Trump’s strengths. In a February poll from The Citadel School of Humanities and Social Sciences, 85 percent of likely GOP primary voters in South Carolina said that they supported the use of state funds under Gov. Henry McMaster’s order to deploy South Carolina National Guard troops to the U.S.-Mexico border last year, while just 11 percent opposed the decision. Among South Carolina voters overall, 57 percent supported the decision, while 35 percent opposed it. This echoes Trump’s position on the issue.

—Mary Radcliffe, 538

I’m reminded that in 2022, Haley stuck her neck out for 1st District Rep. Nancy Mace when Mace faced a Trump-endorsed challenger in the GOP primary. Haley even cut an ad for Mace who went on to defeat her opponent by just 8 points. Mace returned the favor by endorsing Trump over Haley in this year’s primary.

—Jacob Rubashkin, Inside Elections

As they cast their ballots for the former president, many Palmetto State voters had immigration and economy on the brain, according to preliminary results from ABC News exit polling. A staggering 71 percent said they trusted Trump more on border security, compared to 27 percent who said they trusted Haley more, and by 69 percent said they trusted Trump more on the economy. They were unconvinced by Haley’s recent pivot to frame Trump as old and incompetent — 71 percent of voters said Trump had both the physical and mental health necessary to be president, while only 59 percent said Haley did.

As Geoffrey wrote earlier this week, the state’s electorate is part of what gave Trump such a sharp edge tonight, and the preliminary exit polling demonstrates it: 61 percent of Republican voters in the exit polling identified themselves as evangelical white Christians, and of them, Trump won 75 percent of the vote.

—Kaleigh Rogers, 538

Update on the delegate watch: At about 24 percent reporting statewide, ABC News projects Trump has won 38 delegates out of 50 so far. That includes 29 delegates for winning the state popular vote and 9 for winning 3 congressional districts. There are 12 delegates from 4 districts where ABC News has yet to make projections — but Trump currently leads every CD by at least 10 points! But in the district that would be most favorable to Haley, CD-01, home to Charleston, we have few votes. So she could end up getting 3 delegates tonight ... in her home state.

—G. Elliott Morris, 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