By Harriet McLeod
CHARLESTON, South Carolina (Reuters) - Former Republican South Carolina Governor Mark Sanford has gained momentum ahead of Tuesday's election against Democratic political newcomer Elizabeth Colbert Busch, but the House race remains too close to call, a new poll shows.
Sanford has a one-point edge at 47 percent to 46 percent over businesswoman Colbert Busch, the sister of television political satirist Stephen Colbert, according to a survey of 1,239 likely voters released on Sunday by the Public Policy Polling firm in North Carolina.
The margin of error for the poll conducted over the weekend was plus or minus 2.8 percent.
Two weeks ago, Colbert Busch led in the firm's polling by nine points at 50 percent over Sanford's 41 percent.
Sanford once held the First Congressional District seat and is looking to make a political comeback after an extramarital affair marred his second term as governor. More recently, he was accused by his ex-wife of trespassing at her home.
He has taken some of the focus off his personal lapses by depicting his opponent as a liberal in lock-step with national Democrats who are unpopular in the Republican-leaning district, the polling firm and political analysts said.
In the final weeks of the race, Sanford held "debates" with a cardboard cutout of House minority leader Nancy Pelosi on sidewalks and in parks.
"The race is close and it's closing because Sanford has been successful in waging a negative campaign, tying her to the national Democrats," said Mark Tompkins, a political scientist at the University of South Carolina.
"It reflects perhaps her inexperience or perhaps lack of planning that she wasn't ready for this attack. She's let the attack go on," Tompkins said.
Voters in coastal South Carolina head to the polls on Tuesday to decide the victor in a personality-driven race that has drawn national fascination.
The special election is being held to fill the seat vacated by Republican Tim Scott when he was appointed to the U.S. Senate in December.
DEMOCRATS HAVE NOT WON DISTRICT IN DECADES
Colbert Busch, a veteran of the shipping industry who has been director of business development for Clemson University's Restoration Institute for five years, is making her first bid for political office.
A Democrat has not held the seat in more than 30 years, and a win by Colbert Busch would not shift the balance of power in the House of Representatives, where Republicans have the majority.
Sanford represented the district from 1995 to 2001 before serving two terms as governor.
The Democratic Congressional Campaign Committee and House Majority PAC accused him in ads of deserting the state in 2009 when the then-married governor tried to hide a six-day visit with his mistress in Argentina by saying he was "hiking the Appalachian Trail."
He is now engaged to the woman, Maria Belen Chapur, who appeared with Sanford at his primary victory party.
The National Republican Congressional Committee dropped its financial support of Sanford's campaign in April after revelations that his former wife had accused him of trespassing at her home.
Ahead of Tuesday's election, Colbert Busch campaigned by bus across the district, which includes Charleston and parts of four rural counties and stretches south along the coast to wealthy Hilton Head Island.
Joined by Democratic congressmen James Clyburn of South Carolina and John Lewis of Georgia, Colbert Busch said she was talking to "hardworking men and women" about "creating jobs, getting our fiscal house in order and having a representative who they can trust."
Sanford launched a "No Debt Tour" to push his message of frugality and balanced budgets and campaigned at diners and businesses.
His campaign continued to attack Colbert Busch for accepting campaign donations from unions in the right-to-work state and questioned her ties to the national Democratic party.
"Even today, my opponent failed to offer a single policy difference between herself and Congressman Clyburn or Nancy Pelosi," Sanford said on Monday. "You can't have your cake and eat it too in politics."
Political analysts said the outcome of the race will depend on voter turnout. College of Charleston political scientist Kendra Stewart said the women's vote could be a factor for Colbert Busch in a district where women make up 55 percent of registered voters.
"I think that Sanford will eventually win the race. What we're seeing here is the power of the big R behind the name," said Robert Oldendick, a political scientist at the University of South Carolina.
(Editing by Colleen Jenkins and Nick Zieminski)