It's relatively rare for incumbent South Carolina lawmakers to face a serious primary threat, and the District 110 GOP race between incumbent Rep. Chip Limehouse and challenger Russell Guerard is even more unusual because of the nature of their district.

Other June 10 House primaries

District 94 (Dorchester County, GOP) Incumbent Jenny Horne faces challengers Evan Guthrie and Franklin Smith.

District 98 (Dorchester County, GOP) Incumbent Chris Murphy faces challenger Larry Hargett

This is the seat that covers much of Charleston's historic district, where both candidates live and where their families go back generations.

Former Charleston County GOP Chairman Mark Hartley put it this way: "That's probably the district where there's the most lineage that goes on."

Limehouse's father, Buck Limehouse, has served as S.C. Department of Transportation director and once ran for Congress. Guerard's father, Theodore Guerard, served in the House from 1964-70; his grandfather, Burnet Maybank, served as both governor and U.S. Senator.

One downtown businessman who has been active for years in Republican politics said he knows both candidates and their families and has made up his mind, but he declined to comment for attribution out of concern for appearing to slight one.

"I'm sort of caught in the middle here," he said.

Though both candidates are well funded, their contest has been relatively mannerly and quiet so far, except for a bevvy of campaign signs.

"It's like they're running a City Council race," said another prominent Republican who also asked not to be named for fear of alienating either one. "I'm going to vote," he added, "but other than that, I'm going to stay out of it."

But for all the history of the downtown portion of the district, the race could very well be decided on the other side of the Cooper River. After the 2010 Census, the district was redrawn. About two-thirds of all District 110 voters live in Mount Pleasant.

That could help Limehouse, who grew up in Mount Pleasant and attended school there. Former Mount Pleasant Mayor Billy Swails is a big Limehouse backer, as is former Gov. Jim Edwards.

Current Mount Pleasant Mayor Linda Page said she is staying out of it.

"I haven't seen either one of them out on the campaign trail very much. It's been rather interesting. I'm sure they're spending money. I've seen a lot of signs," she said. "They're both definitely conservative, but I don't think there's an issue that sets them wide apart that I see."

Mount Pleasant Town Councilman Chris Nickels said he is backing Limehouse, despite controversy at the Charleston Aviation Authority, which Limehouse once chaired.

Limehouse made headlines when he tried to get former director Sue Stephens to report directly to him. She later resigned. There was an investigation into alleged meddling in airport construction contracts, and Limehouse's attorney and house colleague, Rep. Todd Rutherford, later said state investigators cleared Limehouse of any criminal wrongdoing. An FBI investigation is ongoing.

"I think Mr. Limehouse, Chip, has acknowledged that the last couple of years for him have not been the easiest of his political career," Nickels said. "Those matters seem to have been resolved, but I'm sure it was a distraction for him and probably a bit of a wake-up call in the congressional run."

Early last year, Limehouse was among 16 Republicans who ran for the open 1st Congressional District seat, but he finished sixth.

Nickels said Limehouse since has reached out to him and others. "Chip has not done anything in my view that should cause him to be disqualified from the job or taken away," he added. "Do I agree with him on everything? No I do not, but I don't agree with anybody on everything."

While the candidates have focused on holding meet-and-greets, going door to door and appearing before civic and neighborhood groups, the campaign could get more heated in the final days.

The intense nature was underscored when former GOP Chair Lin Bennett filed an ethics complaint against Guerard, claiming his campaign material did not carry proper attribution - a claim the House Ethics Committee quickly dismissed.

Republican Charleston County Councilman Herb Sass, who lives in Mount Pleasant, said he is not backing either.

"I'm friends with both of them. I like both of them. I could say great things about both of them," he said, "so I don't want to take a stand on it."

Hartley, who also is supporting Limehouse, said Guerard is definitely more of a legitimate candidate than Limehouse has faced in recent re-election bids, but he feels Limehouse is safe.

"I feel like he's got folks who have voted for him in that district for a long time," he said.

Reach Robert Behre at 937-5771.