— The South Carolina Republican primary has accurately predicted the GOP presidential nominee for the past three decades, often in campaigns that revolved around guns, God and gays.

That track record has established the state as a firewall that snuffs out insurgent candidates who may gain traction in the smaller, quirkier and far less diverse early-primary states of Iowa and New Hampshire.

But with South Carolina saddled with a 10 percent unemployment rate — one of the highest in the nation — the struggling economy is upending the priorities of many so-called values voters, forcing GOP candidates to rewrite their campaign playbooks.

South Carolina’s pivotal role could be enhanced in 2012 because the state is suffering economic woes that both Iowa, with its 6 percent jobless rate, and New Hampshire, where unemployment is 4.8 percent, have managed to avoid. Nevada, another early caucus state, has an even higher unemployment rate than South Carolina’s, but does not have a history of determining the GOP nominee.

“Every cycle, South Carolina is interesting,” said Bruce Ransom, a Clemson University political scientist. “Here you have the values voter versus the economic conservatives. Now, we have economic hard times hitting people who believe very strongly in social issues. It will be a good test in terms of sorting out which message has the sway.”

For much of her adult life, Karen Christmas has been an unabashed values voter. A longtime Sunday school teacher and recent GOP activist, she said issues such as school prayer, gay marriage and abortion used to top her list of priorities as she evaluated Republican presidential candidates.

But since losing her job of 28 years when the Blumenthal Mills textile company shut its doors, the dire state of South Carolina’s economy has been foremost on her mind.

“As I look at candidates, economics is No. 1, because I can’t find work,” said Christmas, 54, a married mother of two grown children who has not had a full-time job since 2009. “They say if your neighbor loses his job, it’s a recession; when you do, it’s a depression. Well, I have a depression going on.”

These days, the GOP candidates swinging through the state are playing up their economic credentials to appeal to such voters.

Former Utah governor and ambassador Jon Huntsman was in South Carolina recently, telling voters about his business experience with his family’s chemical company. Rep. Michele Bachmann (Minn.) delivered a tea party-inspired message last week about the need to cut government to spur economic growth.

Mitt Romney, the former Massachusetts governor who finished fourth among GOP candidates in the state in 2008, has been here pitching his business experience. Tim Pawlenty, who served two terms as governor of Minnesota, has appealed to voters here by emphasizing both budget discipline and religious faith.

Meanwhile, all of the GOP candidates, including former House Speaker Newt Gingrich and Rick Santorum, who served as a Pennsylvania senator, have promoted their conservative stances on social issues. But they also have been careful to tout lower taxes and less government regulation to boost the economy.

“The Republican morality issues are still important, but they are not nearly as important as the economy,” said Chris Drummond, a GOP consultant in South Carolina.

Four years ago, Romney’s Mormon faith was seen as a huge hurdle for GOP voters in South Carolina, the vast majority of whom are evangelical Christians and attend church at least once a week, according to polls.

“That [church-going statistic] alone says something about Romney’s Mormon problem,” said David Woodard, a political scientist who has worked on statewide campaigns in South Carolina. “One thing we know: Those voters are not attending the Church of Latter-day Saints.”

Before the 2008 primary, political operatives in the state recall that someone sent Christmas cards to potential GOP voters that quoted a passage from the Book of Mormon that could be construed to support polygamy. “I’m guessing that was not from Mitt Romney,” said Scott Huffmon, a political scientist who oversees the Winthrop Poll, a statewide survey in South Carolina.

Like Romney, Huntsman is a Mormon. But with the state battling double-digit unemployment, some say the religious issue does not resonate as it might have in the past.

“With 19 percent unemployment in Marion County, do you think I care where you go to church?” Christmas asked.

Vacant tobacco warehouses and abandoned textile mills dot the landscape in Marion County, providing reminders of the area’s once-vibrant economy. But with smoking discouraged, and many textile jobs long lost to overseas competition, the county is in search of a new economic foundation.

“Over the last 10 to 15 years, we had an almost complete exodus of manufacturing jobs,” said John Cox, an official in the Marion County Republican Party.

The economic predicament in Marion County, where unemployment was high long before the recession hit, is similar in much of northeastern South Carolina, a region struggling with high unemployment, an undereducated workforce and an uncertain future.

Other parts of the state, including the coastal tourist hubs, the port and research center in Charleston, and the surging heavy-manufacturing belt around Greenville, are faring better.

“There are really a couple of economies in South Carolina. About half the counties in the state have economic growth,” said Bruce Yandle, a Clemson University economics professor. “In the recession, manufacturing took it on the chin and construction took it on the chin. ”

Despite those differences, GOP voters across the state agree on several tea-party-backed economic ideas — lower taxation and a smaller government role, for instance.

“If you look at who is winning in South Carolina recently, people like Senator Jim DeMint and Governor Nikki Haley, it says the tea party matters a lot, as does a certain economic approach,” Yandle said.

These days, economic issues, rather than social ones, are grabbing headlines.

Local and national politicians have focused much of their attention on the controversy surrounding Boeing’s decision to open a $750 million assembly plant outside Charleston and create a thousand jobs. The facility this month is slated to begin churning out 787 Dreamliners. But it is under the threat of a suit from the National Labor Relations Board, which alleges the company illegally opened the operation in South Carolina in retaliation for past strikes at Boeing plants in Washington state.

Boeing has denied the charge, and the issue has galvanized much of the state in opposition to the Obama administration action.

Another focal point has been Amazon’s decision to open a huge distribution center in Lexington County, just outside the state capital of Columbia, after legislators voted over the objections of other retailers and the reluctance of Haley to grant the company a five-year sales tax exemption on orders shipped within the state. The center is expected to bring 2,000 jobs.

“This is a conservative area, a conservative state,” said Eric Fry, a high school teacher who chairs Marion County’s Republican Party. “I know people don’t want to compromise their beliefs, but with the economic situation being what it is, I know they want answers there as well.”