CHARLESTON, S.C. (AP) -- It's a congressional race featuring political drama, big names and big money -- everything that can make American politics so fascinating.
The special election in South Carolina's 1st Congressional District next month pits a former governor seeking political redemption after his career was derailed by an extramarital affair against the sister of one of the nation's most popular political satirists.
"It's a dream matchup if you're a fan and enjoy politics," said Gibbs Knotts, the chairman of the political science department at the College of Charleston.
The field was set Tuesday night when former Gov. Mark Sanford, who was the top vote-getter in a 16-way GOP primary last month, defeated former Charleston County Councilman Curtis Bostic in the Republican runoff.
He faces Elizabeth Colbert Busch, the sister of comedian Stephen Colbert, in the May 7 special election.
Green Party candidate Eugene Platt will also be on the ballot in the coastal district that runs from northeast of Charleston southwest along the coast to the resort island of Hilton Head.
"Everyone knows who Sanford is and I suspect by the end of this, everyone will know who Elizabeth Colbert Busch is," Knotts said.
The 1st District seat became open when Republican Tim Scott was appointed to fill the remaining two years of U.S. Sen. Jim DeMint's term. DeMint resigned to lead The Heritage Foundation, a conservative think tank.
Four years ago as governor, Sanford was mentioned as a potential GOP presidential candidate. But he vanished from the state for five days and reporters were told he was hiking the Appalachian Trail.
He later returned and tearfully acknowledged at a Statehouse news conference he had been in Argentina visiting Maria Belen Chapur, with whom he was having an extramarital affair. Sanford's wife Jenny later divorced him.
Sanford is now engaged to Chapur, who still lives in Argentina and made her first public campaign appearance with him during a visit on Tuesday night. Sanford said she surprised him by attending.
"She's going to show up when she wants to show up," Sanford said when asked if she would be campaigning. "She's going to be a part of what she wants to be part of and if she doesn't want to be part of it, she won't. She's a very private person."
Sanford has said the couple plans to marry this year.
"Their plans as a couple are personal and we'll keep them personal," campaign spokesman Joel Sawyer said when asked if a date has been set. He said for now, Sanford is focused on the campaign.
Knotts sees Chapur's emergence as part of Sanford's work of political redemption.
"The electorate is going to become no more conservative than he has faced already," he said, noting GOP primary voters are the most conservative and might be judgmental of Sanford's past actions. "I wonder if that was the most important hurdle and the campaign felt like this was an important person in his life, this is his fiancee, and she can take a more public role."
Colbert Busch -- who once worked in Washington as an intern for then-U.S. Senator Ernest "Fritz" Hollings, D-S.C. -- has had a lifelong dream of running for public office. She worked in the shipping industry for years and is now on a leave of absence from her position as the director of business development for Clemson University's Wind Turbine Drive Testing Facility.
Last month, she easily defeated perennial candidate Ben Frasier to win the Democratic nomination in the Republican-leaning district that Mitt Romney captured by 18 points while winning in South Carolina by only 10.
Colbert Busch officially opens her general election campaign on Thursday with a visit to a senior center. In recent weeks she has not commented on the GOP candidates, saying she wanted to wait until her opponent was selected.
Between them, the candidates have raised more than $730,000 and Stephen Colbert is an advantage for Colbert Busch in helping raise more, Knotts said.
"There will be a great deal of money spent and he has the ability to bring people out to events that just having her would be more difficult," he said.
But he said while big names and personality are important, the race will come down to fundamental politics and getting the voters out.
"This is a district that went for Romney pretty handily, so it's going to be a challenge for any Democratic candidate," he said.
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