The South has historically been a politically distinct region. This distinctive character — associated for a long time with strong, conservative Democratic affiliation — has been really important in explaining how the Democratic presidential nomination calendar has evolved. Super Tuesday was initially pushed to strengthen Southern influence and give an advantage to moderate candidates. South Carolina itself was moved to a more prominent spot in the primary calendar because many of its Democratic primary voters are African American — unlike in the traditional early states of New Hampshire and Iowa.

But what does this mean for Republicans? The South has been a Republican stronghold for most of the twentieth century, though Democratic presidential candidates have pulled off occasional victories. And South Carolina hasn't been a distinctly regional primary for Republicans (though Georgian Newt Gingrich won the GOP primary there in 2012). Nikki Haley doesn’t seem to be enjoying much home state (or region) advantage there. And Trump, who is from New York, is consistently popular in the South.

The larger point here is probably that, now that it’s generally in the Republican column, the South has been much less exemplary of unique regional politics, and instead has similar issue positions and priorities as other Republican strongholds.

—Julia Azari, 538 contributor

Only a third of the estimated vote is counted so far, but Trump is leading Haley only 59 percent to 40 percent. If that 19-point lead holds, it would be a pretty far cry from the 28-point lead that the polls foresaw, even though they “called” the correct winner. It’s a good reminder that polls of presidential primaries historically have a lot of error.

—Nathaniel Rakich, 538

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

Let's not sugar-coat this: If the polls are right, Haley will lose badly to Trump in South Carolina, her home state, tonight. According to 538's average of polls, Trump commands the support of 62 percent of likely primary voters compared with Haley's 34 percent. Haley has gained ground in recent weeks, likely a result of voter consolidation as the rest of the candidates dropped out after voting in Iowa and New Hampshire, but so has Trump.

Moreover, according to a poll released this week by Suffolk University/USA Today (which had a very similar breakdown to our average), Trump is leading Haley with most major demographics in the state. The former president leads among Republicans and conservatives, groups that make up 76 and 81 percent of Republican primary voters in the state, respectively. Haley, meanwhile, holds an almost 20-point lead among respondents who described themselves as moderate or liberal and a 26-point lead among those who say the most important issue is the future of democracy.

According to my colleague Geoffrey Skelley, if Trump wins by as much as the polls imply, it would be the best-ever performance for a non-incumbent presidential candidate in South Carolina primary history. (The current record is George H.W. Bush's 28-point win over Bob Dole in 1988.) Surely the Haley campaign will try to spin a victory out of defeat — Trump is no easy opponent, to be fair — but with these numbers there's simply no denying Trump's strength.

—G. Elliott Morris, 538