If Nikki Haley ends up in the South Carolina governor's mansion, one of the people most responsible for her remarkable run will be someone you've almost certainly never heard of.
That's just the way Jon Lerner likes it.
Working from his suburban Washington office in Bethesda, Md., at a safe remove from the political ruckus of Capitol Hill, Lerner is helping guide the Haley campaign in the same stealthy manner that he aided Gov. Mark Sanford's two gubernatorial races.
"Candidates are better served when they remain the focus of public attention rather than their consultants," Lerner, 42, told McClatchy in a rare interview. "I guess I don't have the same kind of ego investment that others in the industry have."
Former first lady Jenny Sanford, who worked closely with Lerner as her ex-husband's gubernatorial campaign manager, said another trait distinguishes Lerner: his unwillingness to work for candidates whose views don't match his own hard-line conservative beliefs.
"He works for clients who he believes in and who reflect his own ideological principles," Jenny Sanford said. "That provides him a sense of purpose and integrity and focus that is lacking in other consultants."
Beyond Haley, a Republican state representative from Lexington, Lerner is consulting for conservative candidates across the country, many of them propelled by tea party activists -- and financed by Sen. Jim DeMint's Senate Conservatives Fund.
Lerner's clients, either directly or indirectly through his work for the Washington-based Club for Growth, include U.S. Senate Republican candidates Ken Buck in Colorado, Mike Lee in Utah, Joe Miller in Alaska, Pat Toomey in Pennsylvania, Ron Johnson in Wisconsin, Marco Rubio in Florida and Sharron Angle in Nevada.
"I am not surprised by the success of the tea party candidates," Lerner said. "They tend to embody the energy of the conservative movement today."
Like DeMint, Lerner rejects many analysts' claims that the hard-line conservatives are splitting the Republican Party and may prevent it from regaining a Senate majority in November.
"I am confident that most, but not all, of them will win their Senate races in November," Lerner said.
In South Carolina, for all the focus on Haley, Lerner's biggest success story this year may be S.C. Rep. Tim Scott, who came out of a crowded field to steal the 1st Congressional District Republican primary in June -- and is on his way to becoming the only black GOP member of Congress.
Associates of Lerner, a devout Jew, say his ethical and religious principles are as important to him as his conservative political beliefs.
So faithful is Lerner to Judaism that he never works on Sabbath. Even in the heated final weeks of a campaign, he drops everything from sundown Friday to sundown Saturday.
"That's a good thing," Mark Sanford said. "The lesson is that you can, in fact, shut down in the middle of campaigns and still have good things happen in the electoral sense."
Among Lerner's dozens of clients throughout the nation over the past 15 years, Sanford was the client in whom Lerner believed most deeply.
Sanford chose him in 2001 to do polls, make ads and craft campaign strategies for his successful 2002 and 2006 runs for governor.
Their professional relationship produced a close friendship that, for Lerner, was ruptured by Sanford's disclosure last year of an extramarital affair with Argentine TV reporter Maria Belen Chapur.
Katon Dawson, for whom the normally unflappable Lerner consulted when Dawson headed the state Republican Party from 2002 to 2009, said the only time he's ever seen Lerner display emotion was after Sanford admitted the affair at a tearful June 2009 nationally televised news conference.
"It was complete anger and betrayal," Dawson said. "I would say the relationship will be strained forever. Jon Lerner worked very hard for Sanford, and it was a betrayal. I am sure he relayed that to the governor."
Lerner and Sanford both say their relationship is cordial. They declined to comment on reports that, despite his personal anger, Lerner advised Sanford to hang tough as the scandal erupted last summer and some allies were urging him to resign.
"All of Mark's friends were saddened and disappointed by last year's turn of events, myself included," Lerner said in the recent interview.
Jenny Sanford, though, said Lerner's feelings were stronger than that.
"Jon is a man of the utmost integrity," she said. "He believed in Mark as I believed in Mark, and I feel very much betrayed."
Lerner does allow that Mark Sanford was well positioned for a White House bid before his affair became public, though the consultant isn't sure the governor would have run.
Lerner, who with his wife has three daughters, is a Minneapolis native and Minnesota Twins fan who stayed up into the wee hours last week watching the baseball team suffer its latest post-season meltdown against the New York Yankees.
So ardent a Twins fan is Lerner that S.C. Sen. Tom Davis, a Sanford confidant who hired Lerner in 2008 to do polling, recalls him taping the team's games during busy campaign weeks -- and then watching four or five of the games, one after the other, during his Sabbath breaks.
Lerner's clients say that unlike many other consultants, he's obsessive about going beyond the top-line numbers and poring through all the "cross-tabs" of his polls.
Nick Ayers, executive director of the Republican Governors Association, said Lerner examines 500 pages of underlying data for each poll, identifying voter subgroups and deriving targeted strategies from them.
"He goes through every piece of demographic data on ethnicity, sex, race, religion, income, ideological divides," Ayers said. "An enormous amount of energy and patience goes into reading each cross-tab. In this town, no one that I know but Jon literally reads every one. A lot of people would say that's odd. I say that's a guy I want in the foxhole with me."