Jockeying for the 2008 Republican presidential nomination is well under way in South Carolina — a key battleground state in the fight for the party’s top prize.

Among the Republicans testing the waters in the state are former New York City Mayor Rudy Giuliani, Massachusetts Gov. Mitt Romney and U.S. Sen. John McCain of Arizona.

Though the contest is a good three years away, experts say it’s not too early for aspiring presidents to be testing the waters in this must-visit, must-win state.

South Carolina is the GOP’s political “gateway” to the South. The winner of the state’s primary normally has momentum heading into a round of Southern primaries.

Starting now is “important for candidates who are not well known,” GOP pollster Whit Ayres says. “If they establish a base early, it would be very helpful for them down the road.”

Potential candidates are taking preliminary steps to establish a beachhead in South Carolina.

They have scheduled speaking engagements, conferred with local political leaders, contacted state campaign consultants and made customary calls to the state party headquarters.

At the inaugural in Washington, for example, state Republican chairman Katon Dawson was approached by potential candidates and their staffs, inquiring about visits to the state and getting a rundown on upcoming political events. The state party’s annual fund-raising gala — the Silver Elephant Dinner, set for April 9 — is expected to draw a crowd.

“I think we’re going to get flooded with these guys,” said Luke Byars, state party executive director.

Dawson has dubbed the event “the kickoff for the presidential preference primary.”

Giuliani, who has expressed an interest in running for president in 2008, has scheduled two S.C. speaking engagements.

On Feb. 9, he will attend a fund-raiser in Columbia for survivors of the Indian Ocean tsunami. On April 18, he will be the keynote speaker at a political fund-raiser for state Attorney General Henry McMaster on Hilton Head Island.

Giuliani’s staff says he is not even thinking about politics now.

Romney will be in Spartanburg on Feb. 21 to address the second annual Presidents’ Day Dinner, sponsored by the Spartanburg GOP.

Romney’s political action committee has contributed money to several Republican organizations in the state, including $1,000 to the Spartanburg GOP.

“That’s why I’m giving him first dibs,” Spartanburg party chairman Rick Beltram said.

McCain’s representatives also recently visited the state. They met with House Majority Leader Jim Merrill, R-Charleston, and political consultant Richard Quinn. Both played leading roles in McCain’s losing primary contest against George W. Bush in 2000, one of the nastiest ever witnessed in South Carolina.

“We had a good discussion,” Merrill said of his meeting with Lanny Wiles, McCain’s advance man in 2000. “They are definitely exploring another race.”

Quinn, the state media consultant for McCain in 2000, said he hopes the senator will run. “If he does, he’ll be very strong in South Carolina. He’ll be well-positioned here.”

But those who had their knives out for McCain in 2000 will be back.

“If he enters the race, he’ll bring more baggage into South Carolina than Delta Airlines,” said Heath Thompson, Bush’s state campaign director in 2000.

Consultant Warren Tompkins, who has close ties to the Bush White House, says he could back anybody but McCain. “He’s always first out of the box to criticize the president.”

However, U.S. Sen. Lindsey Graham, R-S.C., said he’s sticking with McCain if he runs.

All the interest in the 2008 election might seem premature to voters, who went to the polls only three months ago in the presidential race.

“We’re starting earlier all the time because (primaries) are very front-loaded,” said Texas A&M University political scientist George Edwards III. “And if you need to build name identification, you can’t afford to wait. And they have to come to South Carolina because it’s a pivotal primary.”

In recent years, South Carolina has combined with Iowa and New Hampshire to define, and even settle, the battle for the GOP nomination.

For would-be nominees, the state’s first-in-the-South primary can act either as a fire wall to a setback in New Hampshire or a gateway to a Southern sweep.

South Carolina could play that role again in 2008.

But a lot will depend on what Republican Gov. Mark Sanford does. Sanford, who faces re-election in 2006, has been mentioned as a possible presidential candidate and has said little to discourage the speculation.

But if Sanford runs, other candidates most likely would consider him a favorite son in South Carolina’s primary and move on to another state, removing the Palmetto State from the national limelight.

If that happens, Georgia would hold the first important Southern primary in 2008.

“South Carolina’s loss would be Georgia’s gain,” University of Georgia political scientist Charles Bullock said.

Reach Bandy at (803) 771-8648 or lbandy@thestate.com.