A Public Policy Polling survey indicated the Republican candidate -- who left office under a cloud after it was revealed he had an affair -- in Tuesday's 1st District congressional race holds a 1 percentage point lead over Colbert Busch, sister of TV comedian Stephen Colbert, The (Columbia) State reported Sunday.
A PPP survey two weeks ago showed Sanford trailing by 9 percentage points.
A Red Racing Horses poll last week indicated Colbert Busch and Sanford were tied at 46 percent.
Sanford is trying to overcome the revelation of his 2009 affair that clouded his final years as governor, ended his marriage and derailed national political aspirations. During the campaign, ads criticized Sanford for leaving the country while governor to visit his Argentinian lover, who now is his fiancee.
Sanford's polling numbers have risen recently as he has worked to tie Colbert Busch with House Democratic Leader Nancy Pelosi, who is deeply unpopular in the heavily Republican district, The State said. He mentioned Pelosi's name nearly 10 times during his only debate with Colbert Busch last week.