In the debut poll from The Citadel School of Humanities and Social Sciences, 69 percent of likely South Carolina GOP primary voters said they expected Trump to win the primary by a large margin — which would line up with his average polling lead of nearly 30 points. Nine percent said they thought Trump would win in a close election, 10 percent thought Haley would win in a close election and only 2 percent said they thought Haley would win by a large margin. Voters who told the pollster they plan to vote for Trump were especially confident: 89 percent said they thought the former president would win by a large margin, compared to 33 percent of Haley voters.

—Mary Radcliffe, 538

If you're not quite as election-obsessed as us here at 538, please allow me (a person who willfully chose to spend an evening three weeks into her maternity leave watching the GOP debate) to fill you in on the last few weeks.

At the start of the year, there were still six major candidates competing for the Republican Party nomination. By the end of January, only two remained. In Iowa, Trump came out on top with 51 percent of the vote, followed by DeSantis and Haley. Ramaswamy and Hutchinson both dropped out after the Iowa caucuses (Christie dropped out just before), while DeSantis ended his campaign just before the New Hampshire primary, where Trump defeated Haley 54 percent to 43 percent.

So far, though, Haley has refused to throw in the towel, despite trailing Trump badly in polls.

She also did poorly in two additional contests in early February. In Nevada, where Trump wasn't even on the primary ballot (he was on the ballot for the Nevada GOP caucus … it was a whole thing), she still got only 31 percent, with voters preferring the electoral equivalent of "none of the above." And she lagged behind Trump in the Virgin Islands GOP caucuses, too.

I'll have more in a bit about why Haley might still be running, but suffice to say it's an uphill battle against the former president.

—Kaleigh Rogers, 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

If you are looking for something to listen to while we wait for polls to close and results to come in, allow me to suggest our latest episode of the 538 Politics podcast. We talk about what to expect tonight, including how South Carolina's primary electorate is different from that of other early states and how the results might shape what Haley does next. We also had a debate about a recent poll on presidential greatness and looked at polling that suggests the wars in Ukraine and Gaza have created some significant divides within the two parties.

—Galen Druke, 538