"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.