Two months ahead of the South Carolina primary, Republican Sen. Lindsey Graham is campaigning with gusto to ward off any potential political threats along his right flank, where he was thought to be vulnerable to a competitive Tea Party challenge.

But, in fundraising, at least, Graham's campaign appears to be declaring: Mission accomplished.

Not one of Graham's Republican challengers has exceeded $1 million in contributions. Graham's campaign, meanwhile, has raised more than $11.6 million during the election cycle, and ended March with nearly $6.9 million on hand.

But that's less cash than Graham had at the end of last quarter, when his campaign boasted more than $7.6 million on hand, and his fundraising pace has slowed markedly since then.

Graham's campaign on Tuesday reported raising more than $873,000 from January through the end of March — a respectable amount, but only a fraction of the nearly $1.3 million Graham brought in during the previous quarter, from October through December 2013.

"We've shifted more to the retail-politics stage of the campaign," acknowledged one aide familiar with Graham's campaign strategy.

Instead of soliciting donations, Graham has been gripping and grinning his way through a feel-good tour of the Palmetto State, hosting free or low-dollar events that have drawn crowds of tens or hundreds of people.

In March, Graham's events included a lowcountry boil in Beaufort, S.C., that drew roughly 350 supporters; in February, Graham dished up free barbecue in the town of Gilbert.

Graham has also been spending his campaign war chest to amplify his brand on national security issues and to tout his focus on investigating the terrorist attack in Benghazi, Libya, that killed four Americans in 2012 and has become a cause célèbre among conservatives.

"In a dangerous world where the only guarantee of peace is strength, Lindsey Graham stands strong," a male narrator said in a television ad released by Graham last month.

South Carolina's primary election will be held June 10, and Graham has held a commanding lead in public polls. His Republican challengers include Lee Bright, a state senator, and Nancy Mace, who was among the first women to graduate from The Citadel, a prestigious South Carolina military college.