Then, here in the Palmetto State, his path to the Republican nomination will be cemented.
"In most prior elections, Iowa and New Hampshire split. They go for different candidates," Cruz said Saturday in a college auditorium here in the ruby red Upstate region. "South Carolina historically has had the role of picking presidents."
If Cruz predicts that the series will be tied as he and Trump clear the field, South Carolina is being envisioned as the rubber match, the moment when Republicans are forced to decide between two self-stylized conservatives who have deep -- but not dominant -- appeal.
Adopting a mocking, sardonic tone toward Trump that would've been unthinkable even a week ago, Cruz presented South Carolina Republicans with the outline of what is likely to be his argument up until they head to the polls on Feb. 20. Even if Trump appeals to your heart and your emotions, Cruz told audiences in ways both stark and veiled, you need to vet him carefully.
"Any candidate on that stage, no matter how much you like them when they're campaigning, if they haven't stood and fought," Cruz told a Tea Party audience hours away at an event in Myrtle Beach on the hottest day of the Trump feud yet, "you can know to an absolute fact that they wouldn't do so as president either."
As soon as he walked off the tense debate stage in Charleston on Thursday, Cruz suddenly shed any coyness about biting into Trump's persona. Yes, he "likes" Trump, but he is also an "incredible marketer" and a "talented entertainer." Yes, Trump's frustration is well-placed, but he is also "springing out of bed to tweet in a frantic response to the latest polls," as he told reporters with a smile Saturday in Fort Mill.
And his aides, once loathe to even utter anything that could be construed as negative about the GOP front-runner, gleefully shared their favorite parts of Trump's history of political donations, an effort to tie him to New York's foremost liberal Democrats, including Hillary Clinton. Cruz himself looked to isolate Trump and his "New York values" -- in support of partial-birth abortion, gay marriage and gun control -- from a culturally conservative South Carolina GOP electorate. ("I'm curious: Do the people of South Carolina know what New York values are?" he asked with a deep laugh here Friday.)
And even when Trump tried to regain control by making hay of an admitted mistake Cruz made when he didn't disclose certain campaign loans, Cruz's team breathed a sigh of relief as Trump was loudly booed by a Myrtle Beach crowd -- after which he quickly exited the stage.
But as much as Cruz's supporters may think they are the team to dethrone Trump from the king's perch here, most recent polls show Trump up by as many as 20 points. Even if Iowa and New Hampshire result in a split decision, Trump supporters say, there's a confidence South Carolina will be where the line is held -- though his team on the ground is holding cards close to its chest.
"We are actually occupied with work here," said Ed McMullen, Trump's co-chairman in the state, "unlike some other campaigns."
"I think he'll win it, and win by big numbers," said Jim Yates, holding a Trump-emblazoned sombrero and attending his sixth Trump event in the state. "Trump is number one, and Cruz is second, in South Carolina values."
Cruz and his allies are determined to deny Trump the victory that could thwart the momentum he's hoping for ahead of Super Tuesday, a date Cruz has described as his campaign's "firewall." Mike Gonzalez, who runs an influential network of pastors across the state and is helping Cruz, says he's eyeing a scenario in which Trump fails to blow away the field in the first two states and evangelicals in South Carolina make the state a death knell, even if not his Waterloo.
And Cruz's high-powered super PAC network is aiding his ground game more in South Carolina than any other state, as 14 field staffers operate side by side with those on the campaign payroll.
Dan Tripp, who running the group's efforts here, pushed back on labeling what his troops are preparing for versus Trump as a "battle royale," but he knew the state for Cruz wasn't won they could risk losing.
"It's going to set the tone for the beginning of the end," he said.