South Carolina's conservative electorate gives Trump a big edge

South Carolina is known as the Palmetto State, but when it comes to Republican presidential nomination contests, a more apt nickname might be the Kingmaker State. Since the South Carolina Republican Party introduced the state's "First in the South" presidential primary in 1980, the race has often positioned one GOP contender as the unquestioned front-runner moving into later primaries. And over the past four decades, all but one Republican aspirant who won South Carolina went on to win the party's nomination.

In 2024, South Carolina could once again prove decisive in the Republican presidential primary, albeit as a potential final nail in the coffin. Heading into Saturday's contest, former President Donald Trump holds a dominant position in the GOP race over his only remaining major opponent, former U.N. Ambassador Nikki Haley. As a former South Carolina governor, Haley surely hoped a strong home-state showing would boost her chances for the Republican nomination. But while New Hampshire's primary electorate was relatively friendly to Haley (who lost to Trump by 11 percentage points in the Granite State a month ago), a more conservative and religious Republican electorate has helped buoy Trump to a much more commanding polling lead in South Carolina.

Haley has sounded resilient in the face of her underdog status, promising earlier this week that she will remain in the race beyond South Carolina regardless of the outcome. Still, her continued ability to raise money and appeal to voters could be greatly hampered by suffering a much worse defeat in South Carolina than she endured in New Hampshire. With the future of the GOP contest at stake, here is a look at the state of play in the Palmetto State, and why Trump appears on course to claim a sizable victory on Saturday.

Trump could win by a record-setting margin

To begin with, the primary polls give Trump a huge lead in South Carolina. As of Thursday afternoon, Trump led Haley by almost a two-to-one margin, 64 percent to 33 percent, in 538's South Carolina polling average — a gap three times the magnitude of Trump's New Hampshire victory.

Should the polls prove reasonably accurate, Trump could be on his way to one of the largest victories a Republican primary contender has ever enjoyed in South Carolina. For a non-incumbent, then-Vice President George H.W. Bush set the standard with a 28-point victory in the 1988 primary. Bush then won by 41 points while seeking renomination in 1992, the only time the state GOP held a presidential primary in a year when an incumbent Republican president was running for reelection. While Trump is unlikely to best Bush's 1992 record, his lead in our polling average would narrowly outshine Bush's 1988 victory margin.

Now, primary polls have larger average errors than general election polls, so a closer-than-expected result is certainly not out of the question. Yet Haley would need a historically large polling misfire to even run near to Trump, much less win. Consider one of the largest presidential polling misses in modern times: Michigan's 2016 Democratic primary. In that contest, Vermont Sen. Bernie Sanders defeated former Secretary of State Hillary Clinton by 1.4 points after trailing by a little more than 21 points in the polls — about a 23-point error, all told. An error of that size in this year's South Carolina GOP primary would barely get Haley within around 10 points of Trump, not far off her margin of defeat in New Hampshire. To actually win, she would need a polling error around 50 percent larger than the Michigan miss in 2016.

A more Republican, conservative and religious electorate

Despite being Haley's home base, South Carolina is demographically much friendlier turf for Trump than New Hampshire. Exit polls dating back to the 2012 Republican nomination race suggest that South Carolina's GOP primary electorate — like Iowa before it — will be more heavily Republican, more conservative and more religious than New Hampshire voters. All of these are pluses for Trump.

In 2012 and 2016, at least 7 in 10 South Carolina GOP primary voters identified as Republican and about a quarter called themselves independents. By contrast, only around half of New Hampshire's GOP primary voters in 2012, 2016 and 2024 called themselves Republicans, while more than 40 percent said they were independent. As was true in Iowa and New Hampshire, Haley has stronger support among self-identified independents than among Republicans in South Carolina, so a larger share of Republicans voting in the GOP primary should help Trump.

In Iowa's caucuses, where only registered Republicans could participate, the entrance poll found that Trump won a majority (54 percent) of those who identified as Republican versus a plurality (42 percent) of self-described independents. In New Hampshire, which permits unaffiliated voters to cast ballots in the party primary of their choice, the exit poll found that the two groups diverged to a much larger extent: Trump won 74 percent of the vote among Republicans while Haley won 58 percent of independents. Recent polling suggests we might see a New Hampshire-esque split in preferences in South Carolina, too. Mid-February surveys from Suffolk University/USA Today and Emerson College/The Hill found Trump surpassing 70 percent among self-identified Republicans, while Haley narrowly led among independents in each poll.

Now, South Carolina is an open primary state with no party registration, so more self-described independents — and even Democrats — could participate in Saturday's primary. State law allows voters to cast a ballot in only one party's presidential primary, and the Feb. 3 Democratic contest had extremely low turnout. This was partly due to low interest in light of Biden's weak opposition — he won 96 percent of the vote — but it may also signal that some anti-Trump voters stayed home so they could weigh in on the GOP contest. Haley's campaign itself has sought to turn out voters who don't regularly participate in primaries, while groups like Primary Pivot have encouraged voters regardless of party to vote in the GOP primary to impede Trump.

Yet it's still hard to imagine the electorate dramatically shifting from what we saw in 2012 and 2016 to include a much larger share of independents or even Democrats. In fact, 2012 may be instructive: That year, President Barack Obama faced minimal opposition for renomination and ran unopposed in South Carolina, so the GOP primary was the only real game in town. Despite this, there was only a small uptick in the share of non-Republicans in the primary electorate.

Beyond party identification, Trump also stands to benefit from South Carolina's larger share of conservative-minded voters. More than 35 percent of GOP primary voters identified as "very conservative" in South Carolina's 2012 and 2016 races, whereas New Hampshire's electorate didn't surpass 26 percent in that category between 2012 and 2024. And Trump does best among the most conservative voters in the polls: For instance, a late January Monmouth University/Washington Post poll of South Carolina found Trump garnering 80 percent support among very conservative voters, compared with 59 percent among somewhat conservative and 33 percent among moderate/liberal voters. This is a major shift from 2016, when Trump attracted more support from less conservative voters, while Texas Sen. Ted Cruz tended to do best among those who labeled themselves very conservative.

Trump's greater appeal among conservatives is also connected to his increased support among white evangelical Christian voters. Voters who fall in that category tend to identify as more conservative than non-evangelicals, and they will likely make up a majority of South Carolina's GOP primary electorate. In 2012 and 2016, about two-thirds of GOP primary voters there identified as white born-again Christians, compared to less than a quarter in New Hampshire. That this group would be so numerous adds up: South Carolina ranks in the top one-third of states based on population share that identifies as white evangelical Christian (23 percent), according to the Public Religion Research Institute, and white evangelicals rank among the Americans most likely to identify as Republican.

The late January Monmouth University/Washington Post poll found Trump attracting support from 69 percent of white evangelicals, compared with 46 percent of other voters. Meanwhile early February surveys from Winthrop University and The Citadel didn't separate out white evangelicals, but found Trump at 70 percent or better among evangelical Christians, compared with around 60 percent among those who didn't identify that way. (Note that most voters will be white: In South Carolina's 2012 and 2016 GOP primaries, 98 percent of voters identified that way, according to the South Carolina Election Commission. Though participation among voters of color may tick up this year, they will remain a very small part of the primary electorate.)

What to watch as the returns come in

As the state begins to report vote counts on Saturday evening, we'll be watching county and broader regional results to gauge the potential scope of Trump's advantage. The 2016 Republican primary can serve as a helpful starting point for understanding where Trump's strongest — and weakest — areas might be. Back then, Trump won by 10 points, garnering 32 percent of the vote. His two main rivals, Florida Sen. Marco Rubio and Cruz, each received about 22 percent, with Rubio finishing second. Yet with a crowded field — three other candidates won between 7 and 8 percent — Trump's showing was good enough to carry all but two counties in the state.

In 2016, Trump's strongest-performing area was in the state's northeast: He won about 44 percent of the vote in the Myrtle Beach-Florence media market, which made up close to one-eighth of the state's vote. The northeastern part of the state should once again be one of Trump's strongest in 2024: The Citadel's poll found him winning around two-thirds of the vote in that media market, and Suffolk found him garnering about 7 in 10 voters in the Pee Dee region, which overlaps much of the same turf. He's also poised to improve in a critical area of (relative) weakness in 2016: the vote-rich Upstate area around Greenville in the state's northwest, which contributed about one-third of the 2016 primary vote and was Cruz's strongest region. Both The Citadel and Suffolk polls found Trump at around 70 percent support there. His strength in the Upstate region — the most evangelical-rich part of the state — will come in part from having won over very conservative and white evangelical voters more likely to have backed Cruz in 2016.

By contrast, Haley will likely do best in Rubio's strongest regions, like the more affluent and well-educated Charleston area, where Haley pulled in between 40 and 50 percent of respondents in The Citadel and Suffolk polls. Charleston County proper was one of just two counties that Rubio carried in 2016, the other being Richland County (home to Columbia, the state capital) in the center of the state. Haley could be competitive there, too, as the Suffolk poll found her running within a dozen points of Trump in central South Carolina. Overall, the Charleston and Columbia media markets made up about one-sixth and one-fifth of the state's 2016 GOP primary vote, respectively.

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Headed into Saturday, the win-loss outcome in South Carolina lacks much drama. Trump is a huge favorite to carry the Palmetto State, leaving the final margin — and Haley's response to it — as the main point of interest. Were Haley to depart the race right after South Carolina, the 2024 Republican race would rank as the shortest competitive presidential primary since the modern nomination process began in the 1970s. Though she insists that her plan is to soldier on into March regardless of Saturday's outcome, despite trailing Trump by huge margins most everywhere, a decisive loss in her home state could change that calculus.