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Voters cast their ballots during the first day of early voting at a polling station in Charleston, South Carolina, on February 12.

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Former President Donald Trump has a lead in the Republican presidential primary, but the process is far from over. The next step is South Carolina’s primary, which takes place on Saturday, February 24. Here’s what to know:

Who is running in the South Carolina Republican primary?

The major candidates include Trump, the current front-runner to get the Republican nomination for the third straight presidential election. His top rival is former South Carolina Gov. Nikki Haley, who also served as US ambassador to the United Nations for part of Trump’s term as president.

Who can vote?

South Carolina’s primaries are open, which means any registered voter can take part in either the Republican primary or the Democratic primary, but not both. The Democratic primary took place earlier in February. President Joe Biden won easily.

Who has been ahead in the GOP primary?

Even though Haley was the state’s governor, Trump has been the clear leader in pre-primary polling. He gets the support of more than 60% of GOP primary voters in several recent polls – far outpacing Haley, who has hovered around 30%.

Trump has held rallies in the state, but much of his campaigning has been done from courtrooms in New York, Washington, DC, and Florida, where he faces a series of criminal prosecutions. He was also ordered to pay $355 million in a civil fraud case last week.

Rather than hurt him, his legal problems seem to have galvanized Republicans around his campaign. He has also used media attention at courts to dominate campaign coverage.

Haley, meanwhile, could suffer an embarrassing loss if she can’t win the state where she was governor.

Haley could lose her own state?

It seems likely, although she scored an incredible, come-from-behind primary win when she first ran for governor in 2010.

She and her allies have far outspent Trump in advertising, spending nearly $15 million ahead of the South Carolina primary compared with the $1.3 million spent on his behalf, although pro-Trump ads have increased in recent weeks. While spending by Haley’s campaign and its allies is far above Trump’s, it’s less than half of what was spent in either New Hampshire or Iowa, two states she lost.

Why is Haley still in the race?

She has sharpened her criticisms of Trump in recent weeks, particularly focusing on the chaos Trump’s trials will bring, his failure to call out Russia over the death of Vladimir Putin rival Alexey Navalny and his and Biden’s advanced ages.

Haley told CNN’s Kaitlan Collins last week that both Trump and Biden are “mentally diminished.”

“I’m not going anywhere,” Haley said. “I am fighting this, because we have a country to save. I’m fighting this because I don’t want my kids to live like this. I don’t want anybody’s kids to live like this.”

01:28 - Source: CNN
Haley on 2024 election: 'It will either be me or it will be Kamala Harris'

If Trump wins South Carolina, is the primary over?

Not technically. It will ultimately take 1,215 delegates for Trump, or anyone, to secure the Republican nomination.

Just 50 delegates are at stake in South Carolina. Heading into the South Carolina primary, Trump has the lead with 63 delegates to Haley’s 17. So there is still a long way to go.

The largest pot of delegates is up for grabs on Super Tuesday, March 5. The first day Trump could reach the magic number of delegates is March 12. But if the polling bears out and Trump decisively wins Haley’s home state, her claim to being a viable alternative gets more questionable with each loss.

It’s also possible that Haley is totally shut out of delegates from South Carolina. Twenty-nine of the state’s delegates will go to the statewide winner, and three delegates will go to the winner of each of South Carolina’s seven congressional districts. So if Trump wins statewide and wins each congressional district, Haley could end up with no delegates from her home state.

View this interactive content on CNN.com

How did Haley become governor in South Carolina?

It was an underdog campaign and an improbable win for Haley in 2010, when she emerged from a nasty primary in which she was the target of mudslinging and a whisper campaign. Haley came from behind at the end of the race for the surprise win, which came only after a runoff because no candidate got 50% of the vote on primary day.

Why was the Democratic primary on a different date?

South Carolina has an unusual practice of letting each party pick the date of their presidential primary, and they’re typically held on different days.

Democrats wanted South Carolina to be the first big event on their calendar. It’s the state that revived Biden’s campaign after early losses in Iowa and New Hampshire in 2020 and is much more diverse than either of those two traditional early states.

Biden won the Democratic primary on February 3 with more than 96% of the vote.

01:15 - Source: CNN
Joe Biden celebrates win in South Carolina primary

What are the state’s demographics?

As of the 2020 Census, the state was about 62% White, about one-quarter Black and nearly 7% Hispanic. But the Republican primary voters are overwhelmingly White. When Trump won the South Carolina primary with more than 32% of the vote in 2016, just about 1% of the GOP primary voters were Black.

Does South Carolina have a good track record of picking the party nominees?

It does. Only once since 1980 have South Carolina Republican primary voters not supported the ultimate nominee. That was in 2012, when Newt Gingrich, the former US House Speaker from Georgia, beat the ultimate nominee Mitt Romney, who was then a former Massachusetts governor and today is a senator from Utah.

South Carolina has only become a force in the Democratic process more recently. The only recent election in which South Carolina did not pick the ultimate Democratic nominee was in 2004, when then-Sen. John Edwards, who was born in South Carolina and represented North Carolina in the Senate, beat then-Massachusetts Sen. John Kerry.

View this interactive content on CNN.com

Given South Carolina’s track record of rewarding Southern candidates, it’s notable that Trump, a native New Yorker who now calls Florida home, could beat Haley, a former South Carolina governor.

Is it possible South Carolina will be in play in November?

Probably not. While Biden won nearby Georgia by the narrowest of margins in 2020, Trump won South Carolina with more than 55% of the vote that year. The last Democrat to win South Carolina in a presidential election was Jimmy Carter, who is from Georgia.