Washington CNN  — 

There aren’t many Republicans who believe Lindsey Graham’s mercurial presidential campaign-to-be will actually result in Lindsey Graham becoming president.

But the South Carolina senator’s mere presence in the 2016 race could throw a curveball into the nominating process, forcing his soon-to-be GOP rivals to consider how a Graham candidacy would scramble Republican allegiances in a vital early nominating state.

South Carolina votes fourth in the lineup of leadoff states, after Iowa, New Hampshire and Nevada. But Palmetto State Republicans cherish their role as the first southern primary. And for six straight contested primaries beginning with Ronald Reagan’s win there in 1980, the state winnowed the early field and correctly picked the eventual nominee, always the preferred choice of the GOP establishment.

But the state’s reputation took a hit in 2012, when Newt Gingrich, backed by the state’s restive conservative wing, throttled Mitt Romney, the ultimate nominee, in what was essentially a mano-a-mano showdown between the two candidates.

In 2016, South Carolina Republicans are anxious to recover their We-Pick-Presidents reputation. But the state’s GOP primary is becoming decidedly more complicated for outside contenders: Graham has grown more serious about the race over the last two weeks, according to Republicans who have spoken with him recently.

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Last Friday afternoon, Graham convened a meeting of his high command at his Columbia political office and left them with the clear message that he is no longer just testing-the-waters, but preparing for a full-blown campaign. The foreign policy hawk has hinted at his intentions publicly, too, hiring a pair of national political operatives and delivering what was billed as a “major” foreign policy speech this week at the Council on Foreign Relations in New York.

‘Serious’

“Lindsey is serious,” said Trey Walker, who steered John McCain’s two primary campaigns in South Carolina and attended the Graham meeting in Columbia. “He was adamant that he is serious. He thinks he has a role to play in Iowa and a role to play in New Hampshire. He was giddy about how well received he was in New Hampshire. He believes very passionately that he has the unique ability to bring national security issues into this race unlike any other candidate, that there is a void he can fill that is unique to his experience on his issue.”

If Graham runs, few Republicans say he would have the same kind of “favorite son” impact that Iowa Sen. Tom Harkin had in his own state during the 1992 presidential race. At the time, other Democrats bypassed the Iowa caucuses instead of competing with a surefire winner who was deeply popular with the Democratic base.

“It definitely doesn’t hurt being from South Carolina, but just because you are a sitting senator, that shouldn’t be an automatic berth to win a primary, especially when you are talking about representing our party at the highest office,” said Glenn McCall, one of South Carolina’s three members on the Republican National Committee. “From my conversations with grassroots folks, he will have to compete like everyone else in the race. Lindsey has his followers, but he can’t rest on those laurels. It will be wide open.”

Graham is little more than a blip in national Republican polls, and most media organizations have not even bothered to put his name on surveys. But in his own state, Graham has a muscular political network built up over 23 years in politics, and they are remaining loyal to their man. Republican staffers and donors who might normally be inclined to back establishment-friendly hopefuls like Jeb Bush or Scott Walker or Chris Christie are assisting Graham as he builds a campaign.

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Graham, too, has the potential to crowd the establishment side of the GOP contest, splitting moderate voters and opening the door once again to an insurgent on the right. Political professionals who depend on South Carolina’s national relevance every four years worry about the scenario further diminishing the state’s trusted voice in the process, but a newer generation of devoted tea party conservatives are more enthusiastic about the idea.

“If Lindsey runs, the big winner in this is Rand Paul,” said South Carolina Rep. Mick Mulvaney, who is sympathetic to Paul but stressed his admiration for Graham and Rick Perry, who he endorsed in 2012. “There is 46% of the Republican primary electorate that can’t stand Lindsey. If they are looking at the race, they aren’t going for Lindsey or Jeb or Christie. They are going to be for Rand.”

Complicated standing at home

That Graham lacks any kind of field-clearing power in his home state speaks not only to the slapdash feel of his darkhorse candidacy — his announcement this year that he was forming a “testing the waters” committee surprised even his friends — but also to his complicated political standing back home.

Graham is a known figure in Washington thanks to his frequent Sunday show appearances and passionate support for a strong national defense and immigration reform, both of which have led him to clash with the Obama administration as well as conservatives in his own party. Those two issues alone seem to be animating his potential campaign.

But his political career in South Carolina has been subject to less national scrutiny.

At home, Graham is a masterful retail politician, well-connected, bursting with energy and frequently on the phone with his advisers in Columbia gathering intelligence about the latest goings-on (he does not use e-mail). With his re-election to a third Senate term last year, Graham has gone from living in the shadows of South Carolina political giants like Strom Thurmond and Fritz Hollings to becoming one of them, among the most capable politicians the state has ever produced. And like Thurmond, who ran for president in 1948 and Hollings, who sought the White House in 1984, Graham now has designs on the Oval Office.

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But unlike his former Senate colleague Jim DeMint, Graham did not climb from the state house to the U.S. House to the Senate because of ideology or any rapport with the state’s conservative Republican electorate. Instead, he has scraped and battled with conservatives for years, making enemies on the right. He’s made up for his shortcomings with the Republican base by relying on his instincts, grit, a disarming sense of humor and a ferocious work ethic.

Growing up, Graham’s parents managed The Sanitary Cafe, a small-town pool hall and liquor store in Pickens County, once the heart of South Carolina mill country. His parents died when he was 21, and Graham raised his younger sister, Darline, on his own. Graham, 59, never married, making him one of the Senate’s only bachelors.

GOP establishment

Like his close friend John McCain, Graham has two feet planted firmly in the GOP establishment, arguing for a bigger tent Republican Party and fiercely defending the military and intelligence communities on hot-button issues like surveillance. Though reliably conservative on social issues and gun rights, his votes have frequently put him at odds with South Carolina’s conservative and libertarian wings.

In one memorable 2009 town hall in Greenville, Graham clashed with rowdy libertarians over his vote to confirm Sonia Sotomayor to the Supreme Court.

“I’m not going to leave the Republican Party,” Graham said when one activist asked him why he isn’t a Democrat. “I’m going to grow it. We’re not going to be the party of angry white guys.” His comments were met with a salvo of boos and shouts of “Ron Paul!” “I love this party,” Graham fired back. “I’m not going to be let it be hijacked by Ron Paul.”

Conservatives were eager to knock off Graham when he was up for re-election in 2014. He was vulnerable throughout the campaign, with approval ratings among Republicans that rarely creeped over 50%, dangerous territory for an incumbent.

But conservatives failed to recruit a viable candidate to challenge him, a testament to Graham’s fundraising ability — he raised $13 million for his campaign, a huge sum for a state with affordable media markets — and his loyal and powerful personal network of business leaders, elected officials and political operatives.

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As a result, brand name conservatives in the state like Mulvaney, Rep. Trey Gowdy and Rep. Jeff Duncan all declined to challenge him for pragmatic reasons. Graham ended up thumping his closest primary challenger by 40 points.

Despite a winning streak that goes back to his first state house race in 1992, Graham does not have the kind of profile or conservative goodwill to roadblock other Republican presidential candidates from campaigning in the state. Almost 56 percent of Republican voters in the state do not want him to run for president, according to a poll from Winthrop University this month.

But the same political network that saved Graham in his 2014 primary could impede the ability of other Republican presidential candidate to build a top-shelf campaign in South Carolina. Though they might otherwise be tempted to support Jeb Bush, the leading establishment choice in the GOP field, major South Carolina Republican donors like David Wilkins and Eddie Floyd are sticking with Graham out of loyalty. So is Graham’s political consulting firm, Richard Quinn and Associates, which worked for McCain’s 2000 and 2008 campaigns in the state.

Graham’s infrastructure

“People haven’t focused on the infrastructure Lindsey takes,” Mulvaney said. “Politics is a business in South Carolina. You have three or four really good consultants and pollsters. And in each county and town there is a leading activist. Lindsey will tie a lot of those people up. The Quinns can’t work for Christie or Bush or any of those people. Lindsey knows all of the best operators in every single county and he is going to try to get every one of those people.”

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Then there’s the scenario that no one is talking about: What if Graham actually wins at home?

Graham’s sharp wit, his ease with voters and the media, and his blunt talk seem “custom-built” for the living rooms and town halls of New Hampshire, said one Graham confidante who isn’t authorized to talk about the campaign. A strong showing by the dark horse in the nation’s first primary could electrify Republicans in the next big contest, right on Graham’s home turf.

“The pride of the people of South Carolina would swell,” the source said, perhaps in a fit of wishful thinking. “They’d say, ‘Look at what the homeboy is doing! You’d have people who hate Lindsey’s guts go vote for him.”