CHARLESTON, S.C. – The Trump-Truthers are running out of arguments for why “The Donald” can’t win the Republican nomination, and on Saturday, Trump could end that discussion entirely.

With a victory here -- coming on the heels of a blowout in New Hampshire -- Trump would not only prove that he can win the primary, he’d cement himself as the race’s frontrunner.


A Trump win would also set off a desperate scramble within the party to unhorse him before he scores runaway victories across the conservative south, building a lead large enough in the delegate race that his rivals will struggle to reel him back in.

Ahead of the primary, however, the most formidable of those rivals are spending much of their energy attacking each other. Ted Cruz and a rejuvenated Marco Rubio have built expectations around a strong finish here, and they’ve spent the last few days trying to draw blood from each other.

Perhaps the most clarifying part of the race will be among the losers. A slew of murky polls puts Jeb Bush, John Kasich and Ben Carson at the bottom of the pack, though all three have vowed to keep running no matter where they finish. Kasich may get a pass, as he’s hung his long-shot strategy on later states farther north. But for Bush and Carson, a weak finish would amplify a growing chorus of calls to leave the race.

Here’s a look at the scenarios for each contender and the stakes in South Carolina:

Donald Trump

Polls show Trump as the prohibitive favorite, a finish that would demonstrate his campaign can win both here -- a socially conservative southern state -- and in New Hampshire, where a more secular conservatism holds sway among the GOP faithful.

Saturday's contest is something of a proving ground, too: Trump's bluster and bravado backfired in Iowa, where he lost to Cruz after months of touting a lead in the polls, but it led him to an overwhelming victory in New Hampshire 11 days ago.

South Carolina, though, is the gateway to the south -- a signal that Trump’s act is likely to play well in the half-dozen southern states that vote on March 1, when the GOP will dole out the largest pot of delegates on any single day of the primary. If Trump dominates, Republican leaders may have to start practicing the phrase “presumptive nominee Trump.”

Trump has flirted with danger since the spotlight turned to South Carolina. He’s skewered George W. Bush -- still a popular figure here -- as a liar for taking the country to war in Iraq over faulty intelligence.

There’s also his tiff with the pontiff. The Pope accused Trump Thursday of not being a Christian for his “build-a-border-wall” rhetoric on immigration. Trump criticized the pope in return as insufficiently sensitive to the impact of illegal immigration and drug trafficking on the United States.

Trump has proven immune to such controversies time and again in the primary, grabbing free publicity from all the media attention and demonstrating to his supporters that he won’t back down. Thus far, there’s little evidence his latest tiffs with the former president and current pontiff will be any different.

For now, signs suggest that the flap will be a wash, and perhaps even a slight boost for Trump.

The latest Real Clear Politics polling average puts Trump solidly in first with about a third of all Republican support. Cruz and Rubio are nearly deadlocked with about half as much backing apiece. Bush and Kasich clock in at about 10 percent each, while Carson registers about 6.5 percent.

Ted Cruz

The Texas senator has been besieged since he set foot in South Carolina. Reviled by a Republican establishment that in some ways would prefer a Trump election, Cruz has faced some of the sharpest barbs of the cycle – squeezed by Trump and Rubio, who have taken to calling him a “liar” at every turn.

They’ve zoomed in most forcefully on the senator’s campaign tactics. It began, they argue, with the Cruz camp’s decision to spread a false rumor in Iowa that Ben Carson was leaving the Republican contest.

Since then, Rubio has blasted Cruz’s campaign for Photoshopping an image to make him look cozy with President Barack Obama, and they’ve accused them of manufacturing a viral Facebook post suggesting one of his top South Carolina surrogates, Rep. Trey Gowdy, was deserting him for Cruz. Cruz and his team have denied any part in the Facebook post, and have minimized the importance of the composite photo.

Cruz’s strength is evident, however, in the reception he gets in front of evangelical crowds, a more potent force than they were in moderate New Hampshire. Trump has done well with evangelicals, too, so South Carolina will test Cruz’s strength in this community and offer a window into his likely performance across the South next month.

The contest is also a test of whether his omnipresent support on talk radio and among conservative and tea party leaders translates into a groundswell of grassroots support.

Marco Rubio

If anything, Rubio’s best week of the race has served to ratchet up expectations for a strong second-place finish.

After stumbling to a fifth-place finish in New Hampshire, Rubio has found his footing in South Carolina, the home of many of his top campaign aides. He’s been buoyed by staunch support from leading establishment figures, from Sen. Tim Scott to Gowdy. But the most potent endorsement came Thursday from popular Gov. Nikki Haley, who quickly cut an ad urging voters to back the freshman Florida senator.

Haley has the support of nearly 81 percent of Republicans in her state, according to a December poll from Winthrop University, and she’s gained national prominence for her successful effort to remove the Confederate flag from government buildings.

Cruz has worked to frame Rubio’s solid week as proof that anything other than a victory should be viewed as a disappointment. But Rubio’s people have downplayed the good vibes, saying anything in the top three is a win here. Anything but a top three finish – and perhaps even a top two finish – could rattle Rubio’s suddenly bullish backers about his long-term odds of overtaking Trump.

Jeb Bush

The former Florida governor’s campaign is on death watch. Donors are deserting and the operation is low on cash. Though Bush has pledged to forge ahead, anything but a resurgence would deprive him a theory of the case.

He brought his brother, the former president, onto the trail for him. His mother, former first lady Barbara Bush, also made an appearance. Bush found new energy after his feistiest debate performance of the campaign last weekend. But hope began to fade as Trump continued to control the narrative of the race. Haley’s endorsement of Bush’s Florida rival may have been the final insult.

It would make a stunning coda for the onetime frontrunner for the GOP nomination. Pressure on Bush to exit the race -- and create space for Rubio to consolidate establishment support -- will intensify if he fails to top the senator.

Still, Bush has sent signals that he’s geared up for the long haul. The question is, if South Carolina isn’t the place to make a stand, then where else? Trump holds dominant leads in polling of Florida, which votes March 15, and a battle with Rubio for preeminence there might only serve to deliver 99 delegates to Trump in one of the primary’s first winner-take-all states.

John Kasich

The bad news for Kasich is that polls leave him closer to the bottom of the pile than the top. The good news is that he’s basically playing with house money anyway: a surprise finish in South Carolina would be more evidence that he’s building a head of steam, but it’s nothing he’s counting on. He has a long-shot strategy to win the nomination, and for better or for worse that’ll be as true after the primary as it was before.

The Ohio governor’s upbeat message and rejection of the dark politics of the moment has led to memorable interactions on the trail here, but South Carolina was never going to be friendly territory for the northern governor with a centrist streak on economics.

And his strategy assumes he'll muddle through the next month -– when predominantly conservative states will boost candidates like Trump and Cruz -- until he reaches Michigan on March 8 and his home state on March 15. (Ohio is also a winner-take-all state for delegates.)

Still, South Carolina is a chance for Kasich to prove his strong New Hampshire showing would have a positive spillover further south. And Newt Gingrich, who won the primary here in 2012 after a last-minute surge, told POLITICO that Kasich has a sneaky chance to surprise. He has a particular opportunity, the former House speaker said, to pull votes from the retirees in Myrtle Beach, many who migrated from the northeast, as well as from more moderate confines of the southern coast.

“Kasich carries people who identify themselves as liberals. Kasich’s going to be a moderate, independent candidate coming out of all this,” Gingrich said.

Kasich is already planning to redirect his attention to Massachusetts and Vermont, two March 1 states that offer him the likeliest chance of success before the Midwest states vote. But if he can score a double-digit performance, he might have a little more cushion to grind through Super Tuesday.

Ben Carson

The retired neurosurgeon has polled consistently at the bottom of the pack, but he’s within striking distance of Bush and Kasich. He has suggested that an undetected surge of support could land him in the top three, a finish he argues would upend the entire race.

There’s little evidence that such a surge is coming. Carson’s campaign, which briefly led polls in the fall, has been grasping for a second life since the beginning of the year, when Carson reconfigured his leadership team. He’s since slashed a bloated staff and turned on a spigot of policy pronouncements he argues have added heft to his candidacy.

But he’s still dogged by concerns about his foreign policy chops. It’s why he spent the second-to-last day of the campaign in Charleston at the Citadel. He’s also been, perhaps vainly, arguing that his soft-spoken nature shouldn’t be confused with weakness –- nor the volume of Trump or Cruz confused with strength.

Carson has also made a last-minute appeal to black voters, a constituency that rarely votes in Republican primaries but that he believes he has a unique opportunity to win. Carson has been an icon in the African American community since his groundbreaking 1989 separation of German Siamese twins. His rise from poverty in Detroit to prominence in medicine has been a staple on reading lists in predominantly black communities across the south.

But polls suggest that African American voters here are poised to overwhelmingly cast ballots for Democrats, leaving little room for a groundswell of support.