If Mark Sanford’s quest for redemption falls short in the 1st Congressional District race, he may well point to a stunning 24 hours as the turning point.

Sanford’s promising chance at beating Democrat Elizabeth Colbert Busch in the Republican-leaning district began to fray at the edges Tuesday night when fresh details about his messy family life leaked out.

More unflattering information about his personal life emerged Wednesday, followed by a decision by the National Republican Congressional Committee to back away from the former two-term governor and ex-congressman.

There also was a report in The Washington Post that two of his sons were upset by his former mistress and current fiancee Maria Belen Chapur’s appearance at a runoff victory celebration on April 2.

It all added up to renewed questions about how much Sanford has rehabilitated himself — and to a step backward for his campaign.

“It’s certainly become a more competitive race in light of the events over the past 24 hours,” said Gibbs Knotts, chairman of the College of Charleston political science department.

Richard Quinn, a veteran S.C. Republican political consultant, agreed that the revelations hurt Sanford.

“It is a Republican district, so he’s still likely to win,” Quinn told The Washington Post. “But because of his personal flaws he may not.”

Lowcountry Republicans, such as former Charleston County GOP Chairman Mark Hartley, predicted that Sanford would prevail in the district that went for GOP presidential hopeful Mitt Romney by 18 points.

“People either have a positive or a negative view of him or, quite frankly, even a ‘I’m-going-to-hold-my nose-and-vote-for-him-because-he-has-an-R behind-his-name,’ ” Hartley said of Sanford. “I don’t see how this is going to impact one way or another.”

The latest developments could damage Sanford’s appeal to women, who make up 55 percent of the district’s registered voters and who already viewed him less favorably than men.

Charm Altman of Charleston, president of the S.C. Federation of Republican Women, said the dirty laundry won’t affect her support.

“We’re not electing a saint; we’re electing someone that’s going to help government,” she said. “His personal life is his personal life.”

Sanford released a statement Wednesday attempting to explain what happened on the night of Feb. 3,, which was the subject of the news that broke Tuesday night.

He said he dropped by his ex-wife’s home on Sullivan’s Island that day to watch the Super Bowl with his 14-year-old son, who was home alone.

Jenny Sanford, who notified Sullivan’s Island police in 2011 that Sanford previously trespassed on her property in violation of their divorce agreement, filed a complaint about the incident on March 23 in Family Court.

“I tried to reach her beforehand to tell her of the situation that had arisen, and met her at the back steps under the light of my cellphone when she returned and told her what had happened,” Sanford said in a statement.

He declined further comment except to say he was “particularly curious” how records that were sealed became exposed. The Sanfords’ divorce agreement has been sealed, but other court filings are public record.

The file shows that the Sanfords have sparred at least three times before — over a missed $5,000 child-support payment; over insurance on the Sanford family’s Beaufort County farm; and whether Sanford violated the part of their agreement specifying “no airplanes will be flown at the children” at the farm.

Jenny Sanford told The Associated Press that the child-support payment issue was resolved. Neither Sanford’s spokesman, Joel Sawyer, nor Jenny Sanford’s attorney, Deena Smith McRackan, would comment on the airplane allegation.

Asked about the Feb. 3 trespassing incident during a campaign stop Wednesday at Mount Pleasant’s Boulevard Diner, Colbert Busch’s response was nearly identical to what she previously said when asked about Sanford’s 2009 extramarital affair and his subsequent ethics violations.

“What we’re going to do is we’re going to focus on the job creation, the message to the district, the possible opportunities in the district,” she said. “We’re going to stay focused on the positive, and we’re going to move to (the election on) May 7.”

Sanford faces a Family Court appearance two days after the election.

Meanwhile, the Post reported that one of the Sanfords’ sons met Chapur for the first time during Sanford’s April 2 GOP primary runoff victory celebration at a Mount Pleasant restaurant. Two of his sons, including 14-year-old Bolton, were at the event.

Jenny Sanford confirmed to the Post in a text message, “That was indeed Bolton’s first intro and both boys were quite upset and visibly so.”

As more of Sanford’s personal life became public Wednesday, the National Republican Congressional Committee pulled the plug on the candidate, saying it won’t spend any more money on his behalf.

“Mark Sanford has proven he knows what it takes to win elections,” said Andrea Bozek, an NRCC spokeswoman.

The NRCC had spent relatively little to date, and Knotts said its decision may have more symbolic importance than anything else.

“Sanford is potentially one of 435 members of the House,” Knotts said. “If that group gets too far behind Sanford, is this going to ultimately damage the Republican brand?”

The House Majority PAC, a Democratic Super PAC, said Wednesday it has begun airing an “Air Sanford” ad highlighting his travel and ethics fines and plans to spend more than $100,000 on the race.

Sanford’s campaign also aired its first negative ad of the campaign, a TV spot highlighting Colbert Busch’s donations from labor unions.

Natalie Caula contributed to this report.