GREENVILLE, S.C. — The entire country will be watching South Carolina on Saturday as it picks its Republican nominee for president. Yet one part of the nation may be particularly interested in the outcome: the rest of the South. 

That's because Ted Cruz is hoping the region helps him run up the score on his way to the nomination, a firewall he began cultivating long before many of his rivals even set foot outside Iowa and New Hampshire. Yet on the eve of the first-in-the-South primary, Cruz has continued to register as a distant runner-up to billionaire Donald Trump, begging an uncomfortable question: If Cruz cannot beat Trump in South Carolina, how can he do it in a slew of other southern states that vote 10 days later? 

Cruz's supporters are well aware of the stakes. 

"We want to finish one or two here so that can catapult us into the rest of the South," said state Sen. Lois Kolkhorst of Brenham, who is helping get out the vote for Cruz in South Carolina.

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The urgency was felt last week in the small Upstate city of Abbeville, where a concerned-sounding Cruz supporter asked Tony Perkins, a prominent social conservative backing the senator, how to “combat this steamroller we call Trump right now and the momentum that he has.” The answer, according to Perkins: South Carolina.

“South Carolina is really the place that Donald Trump can be stopped," responded Perkins, president of the Family Research Council. Earlier, Perkins said the state’s primary had the highest stakes yet “because right after that, we’ll roll into Super Tuesday and at that point, the outcome could be decided.”

After Perkins’ response, the man, a local retiree named David Bender, told a reporter he seriously feared Trump could storm through the South on his way to the nomination if he wins the Palmetto State. “This is the firewall right here,” Bender said.

More than a week after the exchange between Bender and Perkins, however, it appears unlikely Cruz will be able to topple Trump in South Carolina, where the billionaire has maintained double-digit leads over Cruz for months in public polling. Instead, the race here has developed into a battle for the No. 2 spot between Cruz and U.S. Sen. Marco Rubio of Florida, who is riding a late wave of momentum thanks to the endorsement of South Carolina Gov. Nikki Haley. 

"That's really the story here: This was going to be the one state that if Cruz didn't do well everywhere else, he was going to run away with South Carolina," said U.S. Rep Darrell Issa of California, a Rubio supporter. "He now looks up to be in third, with the only solace he has that others will be behind him."

The current dynamic is a far cry from earlier this year, when Cruz rallied South Carolinians with the suggestion that they could settle the score if he wins Iowa and Trump takes New Hampshire. Cruz's campaign is denying that the pressure is on them in South Carolina, instead ratcheting up expectations for Rubio given his support from some of the state's most popular Republicans, including U.S. Rep. Trey Gowdy and U.S. Sen. Tim Scott, as well as a campaign with deep ties to the state party.

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Cruz's supporters are also pushing back on the idea that a less-than-dominant showing in South Carolina could imperil his advantage in the southern states set to vote March 1 in what is being called the "SEC primary." On a conference call Thursday with reporters, U.S. Rep. Jack Kingston of Georgia, an SEC primary state, suggested the early attention Cruz paid to the South will pay off regardless of what happens in South Carolina. 

"At that time, he was down in the polls," Kingston said, recalling when Cruz first stumped in his state months ago. "The smart money was actually for Jeb Bush. Scott Walker was flying high."

Since then, Cruz has built up a formidable base of support in Georgia, Kingston added. "A lot of that is under the radar. You don't quite see it."  

Another congressman who represents an SEC primary state, Mo Brooks of Alabama, said the current challenge facing Cruz is broader than just proving his southern-state bona fides in South Carolina. Instead, it's convincing the rest of the GOP field that he is the chief alternative to Trump — an argument Cruz made as soon he touched ground in South Carolina earlier this week, seeking to present himself as the only candidate who knows how to beat Trump.

"Ted Cruz is doing what he needs to do to be positioned to be the candidate that can defeat Donald Trump in a one-on-one matchup," Brooks said. "The question is how long does it take for those candidates who have already lost their races for president to realize it and formally terminate their campaigns?"

As he campaigned across South Carolina on Friday, Cruz did little to tamp down the drama of the race, extensively quoting William Barret Travis as he drew connections between the primary and the Battle of the Alamo. He also debuted a new line against Trump, seeking to speak directly to voters who may be on the fence between the two candidates in the closing hours before the nominating contest.

"It's easy to say you're going to make America great," Cruz said at a Primary Eve rally in Greenville. "You can even put that on a baseball cap. But the question to ask, do you understand what the principles were that made America great in the first place?"

Cruz's supporters are hoping undecided voters see the light — and sooner rather than later. As the crowd let out in Greenville, Donna Pearce, a Cruz volunteer from Georgia, one of the SEC primary states, said it is "very important" to her that Cruz turns in a strong performance in South Carolina so that he has the right momentum as the contest heads deeper into the South.

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"We believe that he has to do well here," she said, "and then it will carry right into the other states."

Polls are open from 7 a.m. to 7 p.m. Saturday in South Carolina.