Looming over the race, albeit from his highly paid perch at the Heritage Foundation in Washington, is former Sen. Jim DeMint, the guiding light of limited-government conservatism for many Republicans here. DeMint and Graham often differed wildly on a number of national issues and they are not close friends, but the two have mostly enjoyed a political truce back home for almost a decade.
DeMint has given no indication that he intends to involve himself in the primary, nor do his protégés seem willing to join the fight to unseat Graham.
"I am going to try to let South Carolina determine who they want for their senator at this time," said Kentucky Sen. Rand Paul, who has sparred with Graham over national security issues and civil liberties in the Senate. "It will be unlikely I will be involved. I haven't completely closed the door."
Even the whiff of involvement by DeMint rankles Graham allies.
Republican professionals were taken aback last week when the Senate Conservatives Fund, a political action committee formed by DeMint, unleashed a radio ad accusing Graham of not doing enough to stop the implementation of Obama's health care reform law.
After the radio ad surfaced, Wesley Donehue, a veteran of DeMint's 2004 Senate campaign, took to Facebook to post a television ad from that race in which Graham appeared, defending DeMint after he was coming under withering attack from his Democratic opponent over a controversial tax proposal. DeMint's internal poll numbers were cratering, Donehue said, "and Lindsey stepped up and stopped the bleeding."
"That would have been a much different race if Lindsey hadn't got involved," Donehue said.
What Graham's opponents need most is money, to boost their profiles among the roughly 400,000 Republicans who are expected to vote in the primary and to keep up with Graham's professional organization.
All three of Graham's announced opponents have traveled to Washington to meet with the Club For Growth, a conservative organization eager to topple Graham that often takes sides in Republican primaries, but the group is staking out a wait-and-see approach to this race.
In the meantime, Mace has picked up the support of a well-connected DeMint donor in Greenville, Bill Lowndes, the chairman and CEO of Tindall Corporation. Others in DeMint's network of financial supporters also are keeping an eye on Mace should she become viable.
"I don't see the other guy as being all that terrible," Lowndes said of Graham. "He is just not like Jim DeMint, and I just see her as more like Jim DeMint."
The Graham campaign's near-term playbook is straightforward: Cut through the din and remind voters of his positions that do square with the conservative base. His aides point out that Graham earned a 92 rating from the American Conservative Union in 2012, has an A-rating from the National Rifle Association, and is opposed to abortion rights and same-sex marriage.
Graham is also a reservist in the South Carolina Air National Guard, not an insignificant biographical detail in a state with eight military bases and a large veteran community.
A well-known workaholic, Graham hasn't had a real political fight on his hands for over a decade, but he harbors an obsession with the minutiae of South Carolina politicking, a fact sometimes obscured by his reputation in Washington as a critical Senate power player and a fixture on the Sunday talk show circuit.
"His job is his lifestyle," Dawson said. "All he does is work."
There's something else Graham's confidantes are fond of pointing out when asked about the prospect of a difficult race: He enjoys a brawl.
His parents ran a small-town pool hall and liquor store in Pickens County, once the heart of South Carolina mill country. Graham was forced to raise his younger sister on his own after his parents died when he was barely 21.
"Lindsey grew up in his family's restaurant and pool room in Central," said one supporter who asked to remain anonymous. "If you back him into a corner, he's likely to break a bottle and come out swinging. He jumps in the big fights in Washington because he's got a little country in him."