Gospel singer Dottie Rambo had written more than 2,000 songs by the time she died in 2008, but she remains best known for a 1970 hymn based on the Irish folk tune “Londonderry Air” (the same melody as “Danny Boy”) which got a memorable performance Monday. “‘Amazing Grace’ will always be my song of praise, for it was grace that bought my liberty,” Herman Cain sang in his warm baritone as he closed his speech at the National Press Club with the chorus that ends, “He looked beyond my faults and saw my need.”

Whatever his faults, Cain’s need as a Republican presidential candidate Monday in Washington was to deny previously private accusations of sexual harassment dating back at least a dozen years which publicly surfaced Sunday in a Politico story headlined: “Exclusive: 2 women accused Herman Cain of inappropriate behavior.” It was one of the most curious articles in the history of political scandals: The article did not name the accusers, reported to be former employees of the National Restaurant Association, where the former Godfather’s Pizza CEO was president from 1996 to 1999, and the description of Cain’s alleged offenses was maddeningly vague. Cain was reportedly accused of “episodes that left the women upset and offended” and “physical gestures that were not overtly sexual but that made women who experienced or witnessed them uncomfortable and that they regarded as improper in a professional relationship.” The article also described “conversations allegedly filled with innuendo or personal questions of a sexually suggestive nature,” and quoted one second-hand source about an allegation of “an unwanted sexual advance” from Cain.

Without anything more specific — and especially without any comment from the accusers, who reportedly signed confidentiality agreements as part of severance agreements with the restaurant association — such accusations would be impossible to disprove, but can be denied, and this was what Cain was expected to do Monday. “In all of my over 40 years of business experience, running businesses and corporations, I have never sexually harassed anyone,” Cain told the capacity crowd at the National Press Club. He said he had been “falsely accused” and that when the accusation was made, “I recused myself and allowed my general counsel and human resource officer to handle it.” As for the reported settlement, Cain said, “I hope it wasn’t for much because I didn’t do anything.”

Buried far down in the 2,100-word Politico article, below all the allegations from unnamed sources, were the names of five former officials of the National Restaurant Association who worked with Cain during his tenure there, and who said the harassment allegations — which they had previously never heard — were entirely uncharacteristic of the man they knew and admired. Denise Marie Fugo praised Cain as “very gracious,” and Mary Ann Cricchio said, “Herman treated everyone great.” So the accusers in the scandal remain anonymous, as do Politico‘s secondary sources, while everyone actually named in the story had only kind words for Cain.

Politico said it had been pursuing the story for “several weeks.” Cain’s spokesman, J.D. Gordon, said other news organizations had previously inquired about the harassment allegations and declined to pursue the story. And while Politico said it had a “half-dozen sources” for its article, those sources did not seem to include the two women who reportedly made the accusations and received termination settlements of more than $10,000 (or, as the article said “in the five-figure range”) from the restaurant association. Although the women apparently did not talk to Politico, the reporters wrote that they had “seen documentation describing the allegations,” thus raising the question: Where did this story come from?

The natural suspicion with any such story is that someone was shopping around opposition research, the dossiers of negative material that campaigns routinely compile on their rivals. Yet those who push “oppo” to reporters are generally careful to do so in ways that don’t leave their campaign’s fingerprints, especially on a story as explosive as this one. In response to questions Monday at the Press Club, Cain said he had no idea whether one of his Republican opponents had pushed the story — a “witch hunt,” he called it. In an impromptu press conference prior to Cain’s speech, his campaign chief of staff, Mark Block, also refused to speculate on that topic. “I would find it hard to believe that anybody with another campaign would do that,” Block said. “But then again, this is politics.”

Indeed, it is politics, where long-ago complaints by former employees can be dredged up and turned into a scandal reported hourly by the cable news networks. And it is politics, where few reporters took notice when Karol Markowicz, who worked closely with Cain on his 2004 Senate campaign in Georgia, strongly defended him in a series of Twitter messages Sunday evening. “I don’t believe…that Cain behaved inappropriately.… He never even bordered on inappropriate in the slightest,” she wrote, adding that she “just can’t believe there’s anything to the charges.” Markowicz called into Mark Levin’s nationally syndicated radio show Monday evening to reiterate her defense of Cain, but other than by me and the Weekly Standard‘s Michael Warren, this obviously relevant testimonial was ignored by the press. Meanwhile, on MSNBC — which showed no interest at all in Markowicz or anyone else vouching for Cain’s good character — Chris Matthews offered one of the Politico reporters “congratulations on breaking this story.”

How much “this story” hurts Herman Cain’s presidential campaign remains to be seen. It is highly unlikely that his accusers will remain anonymous much longer. Reporters will find the women and name them and, without regard to confidentiality agreements, the accusers’ stories will be told somehow. At that point, voters will be able to evaluate the credibility of the accusers and the severity of their accusations in a way they cannot do now, when all they have is “sources say” and vague descriptions of what it is Cain is alleged to have done.

The political scandal factory will keep grinding away, but Cain was smiling Monday at the Press Club when he described the bull’s-eye on his back as the Republican front-runner. Still narrowly leading former Massachusetts Gov. Mitt Romney in the RealClearPolitics national poll average, and even narrowly ahead of Texas Gov. Rick Perry in Texas, Cain has already survived three weeks atop the GOP field. After the Politico story went online Sunday evening, his supporters began spontaneously organizing prayer circles on Cain’s behalf, although his ascent to this point has already seemed miraculous enough.

The Iowa caucuses are barely two months away. If this potentially damaging scandal doesn’t take him down, it may actually enhance Cain’s reputation as a conservative invulnerable to the kind of assaults that the media will surely aim at President Obama’s Republican challenger in 2012. Winning that kind of reputation by surviving such a difficult ordeal would an amazing outcome, although not quite as amazing as the grace that Cain praised in his song at the National Press Club — a performance for which he received a standing ovation.