South Carolina primary 2024: Trump projected to win, Haley vows to stay in the race

Back in 2016, won the South Carolina primary by 10 points, garnering 32 percent of the vote. His two main rivals, Florida Sen. Marco Rubio and Texas Sen. Ted 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. He also won every congressional district, allowing him to sweep the state's 50 national convention delegates.

Trump's strongest-performing area was in the state's northeast, where 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. That region should once again be one of Trump's strongest today: A mid-February poll from The Citadel found him winning around two-thirds of the vote in that media market, and a similarly-timed Suffolk University/USA Today survey 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.

For her part, Haley will likely do best in Rubio's strongest places, like the more affluent and well-educated Charleston area, where Haley pulled in between 40 and 50 percent of respondents in surveys from The Citadel and Suffolk. 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.

—Geoffrey Skelley, 538

In polling conducted since the New Hampshire primary, Trump is viewed favorably by an average of 73 percent of likely South Carolina Republican primary voters, while Haley's average favorability is 51 percent. These numbers are slightly better for the former South Carolina governor than national polling, which, according to 538's tracking, shows 43 percent of Republicans have a favorable opinion of Haley and 81 percent have a favorable opinion of Trump.

—Mary Radcliffe, 538

Spoiler: Whoever wins the Republican primary is probably going to win the state in the general election. Trump beat Biden there by 12 points in 2020, and South Carolina has voted almost exclusively for Republicans in presidential elections since Civil Rights legislation under President Lyndon Johnson flipped most of the South from blue to red. The one exception? The state voted for the Democratic governor of neighboring Georgia, Jimmy Carter, in 1976.

The state reliably votes conservative in other elections too. Its governor, both senators, and six of its seven representatives are Republicans. And many Republican voters there seem fiercely loyal to the former president. Former Rep. Tom Rice, one of ten Republicans who voted to impeach Trump in the House after Jan. 6, was ousted in his midterm primary in 2022.

While many of those newcomers may have come from the more expensive coasts along the Northeast corridor and California, they don't necessarily seem to be changing the state's GOP electorate, as Haley has struggled to overcome Trump's popularity and name recognition among Republican-leaning new residents. Newcomers or no, Haley's challenges winning over voters in her home state seem not so different from her efforts in the rest of the country.

—Monica Potts, 538

Mathematically, Trump can't clinch a delegate majority until the March 12 primaries and caucuses, but he could sew up the nomination earlier if Haley were to suspend her campaign before then. With Haley staring down a potentially sizable defeat in South Carolina, it's possible she could drop out shortly after today's contest. If she did, the 2024 Republican race would rank as the shortest competitive presidential primary since the modern nomination process took shape in the 1970s.

As of today's contest, only four states (plus the U.S. Virgin Islands) have cast ballots. The race ending today — or even after Michigan's primary next week — would beat out the current records for the earliest end date (March 3 in the 2004 Democratic contest) and the lowest number of voting states (19 in the 2000 Democratic race).

An unusually drawn out early voting period likely played a role in winnowing the number of contests candidates could remain viable for: The period from Iowa through South Carolina lasted 41 days, the longest duration from first to last early states since Nevada became an early-voting state in 2008. As a result, Trump could become the presumptive nominee earlier than ever by calendar date and despite barely any states having voted.

Despite that drawn-out early period, the 2024 GOP primary could also be the shortest by the number of days in its competitive period, although that's up for debate. Based on political scientist Caitlin Jewitt's formulation, the 1992 Democratic contest is the shortest ever, having lasted 39 days until former Massachusetts Sen. Paul Tsongas suspended his campaign and left Arkansas Gov. Bill Clinton as the only viable Democratic contender. But the race technically kept going because a candidate with no chance of winning — former California Gov. Jerry Brown — stayed in to push a reform message on issues like campaign finance. If Haley drops out tonight, the 2024 Republican race would last 41 days — a tad longer than the 39-day mark, but also arguably shorter because Brown remained a thorn in Clinton's side beyond it in 1992.

—Geoffrey Skelley, 538