There was rolling thunder and rain outside the Citadel on Monday night, but the lightning was inside the packed auditorium where Mark Sanford and Elizabeth Colbert Busch clashed in the one debate of the one congressional race in the country right now.

Argentinean affairs? A confident Colbert Busch went there, slamming the former governor for leaving “the country for a personal purpose" on the taxpayer dime in 2009.

Sanford returned fire with repeated references to Nancy Pelosi and the labor union donations that have flowed into Colbert Busch’s campaign coffers. The practiced groans of the Colbert Busch staffers and supporters showed that this line of attack is at least as effective as it is hackneyed.

To get a sense of the surreal tacking to the center in the debate, consider this: Democrat Colbert Busch quoted Dick Cheney and Republican Mark Sanford compared himself with Bill Clinton.

From the perspective of the national media, this sometimes seems like a special election between Jenny Sanford and Stephen Colbert. But the scandal and celebrity factors distract from the real drama—Charleston’s first competitive congressional general election in three decades. And according to polls and last night’s debate performance, Democrat Elizabeth Colbert Busch should now be considered the narrow frontrunner in this decidedly Republican-leaning district.

Behind the scenes, her campaign team had been anxious going into this debate, sponsored by Patch.com and the South Carolina Radio network (and which I hosted, introducing the candidates and the rules of the debate on stage at the outset as well as developing the questions with the moderators). A small army of staffers was at the debate site by noon, combing over every detail of the stage and requesting that their candidate be introduced as “businesswoman” Elizabeth Colbert Busch, “Mrs.” not “Ms.”—“she’s a happily married woman,” one staffer explained.

Given that this was Colbert Busch’s sole debate, her team’s nervousness was understandable, but they might have underestimated their candidate. While no doubt a lot of coaching went into Colbert Busch’s performance, her confidence radiated at least as much as the one-liners she deployed with cool determination.

She was relentlessly on message—repeatedly describing herself as a “tough independent businesswoman” who “nobody tells what to do.” But the finesse was most evident in her policy framing, where she taught a master-class in how a Democrat runs to win in a red state.

Alternately distancing herself from liberal positions and then seizing the center, Colbert Busch said “Obamacare is extremely problematic” but then went on to praise the end of preexisting conditions and the law’s provisions that allow children to stay on their parents’ insurance until age 26. She declared herself “a really proud defender of the Second Amendment” but backed the universal background check bill. The nominee of the South Carolina Working Families Party also announced that she was “proud to live in a right-to-work state” and slammed the National Labor Relations Board for overstepping its bounds when it tried to block Boeing’s local expansion of Dreamliner manufacturing. Most of all, she presented herself as a passionate, independent-minded moderate who can help change the tone in Washington. “We have got to come to the middle.” she said. “We have got to be reasonable.”

Colbert Busch’s clearest statement of conscience and biggest political risk came when she announced her “full support” for “marriage equality”—quoting Dick Cheney’s enduring observation that “freedom means freedom for everyone.” Her campaign had previously deleted a Tweet to that effect (among some 500 that have been deleted), but she did not try to dodge the issue during the debate. This says a lot about the courage of her convictions when it comes to civil rights, as well as how much the issue of marriage equality itself has ceased to be a radioactive third rail, even in the urban South.

The issue of gay marriage also brought about the most memorable line of Mark Sanford’s debate. After articulating his belief that the issue should be decided state by state, Sanford responded to a question about his past congressional votes for the Defense of Marriage Act and the impeachment of Bill Clinton by—in his words—“reversing the question.” “Do you think President Clinton should be condemned for the rest of his life for a mistake he made in his life?"

Mark Sanford’s style was loose and laconic compared to Colbert Busch’s tightly focused intensity. But the man brings the wonk, happily discussing details of past policies that earned him taxpayer-protection awards as well as an endorsement from the Sierra Club (and, he noted in an early jab, a $500 dollar donation from Colbert Busch for his first gubernatorial campaign). The command of substance did not clearly translate to emotional connection with the divided audience. The closest thing to an evident debate strategy was his repeated attempt to connect a vote for Colbert Busch to a vote for Nancy Pelosi—he clearly wants to run against the San Francisco Democrat.

In an interesting attempt at political judo, Sanford has also tried to turn his unceremonious dumping by the Republican National Congressional Committee into an asset, highlighting the hundreds of thousands of dollars that the Democratic Congressional Committee and other affiliated groups have poured into Colbert Busch’s campaign in an attempt to flip this seat. “It’s not believable to me that someone gives you a million dollars and not expect something in return,” he said, calling for campaign finance reform.

The closing statements symbolized the candidates’ contrasting styles, with Sanford hitting fiscal conservative themes about the existential threat of deficits and debt that have been the policy calling card of his tumultuous political career. In turn, Colbert Busch presented herself as optimistic and forward-looking—the signature move of a candidate who is feeling confident and trying to tie her opponent to a failed past. “The sky is not falling, Henny Penny,” she chided. “In fact our best days are ahead of us."

After the debate, Colbert Busch’s supporters crowded around her in a cluster recalling a high school basketball team, with high-fives and shouts of “that was awesome!” Sanford was surrounded by a phalanx of cameras and reporters, wondering whether South Carolina’s would-be “comeback kid” had met the end of redemption road.