Politics often being a contest of survival at all costs, it's not surprising that Herman Cain, harassed by allegations of sexual harassment, has tried to pin the blame on the camp of Republican presidential nominee rival Rick Perry.

In an interview with the business magazine Forbes, Mr. Cain indicated he believes the source of the original story in Politico was a Republican political consultant who worked for his failed 2004 campaign for the U.S. Senate in Georgia and now is affiliated with the Perry campaign.

Mr. Cain told Forbes he mentioned one such allegation to the consultant, Curt Anderson, in 2003 in a discussion of possible "opposition research on me." That would be the digging up of information that could have been harmful to his election chances. Mark Block, Mr. Cain's campaign manager, then called on the Perry campaign to apologize, but Mr. Anderson denied ever hearing of the allegations against Mr. Cain until he read them in Politico. And Mr. Perry's spokesman, Ray Sullivan, called the charge that his campaign had leaked the story "patently false."

So the political upshot of the whole affair is to give "legs" to the story; that is, to keep it walking through gossip-land for several more days, with uncertain import either in hurting or helping Mr. Cain's presidential aspirations. It's not unheard of for a rival campaign to dish dirt against an opponent, but doing so and getting caught carries high risk in itself.

The best example occurred in the contest for the 1988 Democratic presidential nomination. Two reporters, one from the Des Moines Register and the other from the New York Times, received video tapes of a speech made by a British candidate for prime minister, Neil Kinnock. It bore a remarkable resemblance to words uttered without attribution by Democratic candidate Joe Biden in the run-up to the Iowa precinct caucuses.

The resulting stories led Mr. Biden to withdraw from the race under a shower of allegations of plagiarism. Some in the Biden campaign pointed fingers at the rival camp of Democratic presidential candidate Rep.Dick Gephardt of Missouri, and others at that of Gov. Michael Dukakis of Massachusetts, as the leaker of the Kinnock tape.

Mr. Dukakis particularly was affronted at the suggestion, saying he would be "very angry" and "astonished" if anyone from his staff had been involved because all in his campaign knew "how strongly I feel about negative campaigning."

It turned out, however, that his campaign manager, John Sasso, admitted he had authorized the leak, and he was forced to resign. He was perhaps the key supporting figure in the Dukakis campaign, and although he was brought back late in the game, Mr. Dukakis lost the election to then Vice President George Bush.

Earlier in the same campaign, Sen. Gary Hart of Colorado had been forced out of the race on detailed allegations and evidence of sexual misconduct. Rival campaigns also had been blamed, if not for disclosure then certainly for political exploitation and rumor spreading.

But allegations of sexual harassment have risen to the forefront of political flashpoints particularly since the Supreme Court confirmation hearings of Justice Clarence Thomas, who was accused by former federal agency employee Anita Hill. In Senate Judiciary Committee hearings chaired by the same Joe Biden, Mr. Thomas as an African-American nominee blatantly cited his race as cause of what he called "a high-tech lynching" to deny him the court seat. He finally was narrowly confirmed in a vote that has been challenged by many Thomas critics to this day.

Mr. Cain's allegation that the Perry camp was responsible for stirring up this latest political hornet's nest is only likely to increase pressure on him to be more forthcoming about the details of the case in which his employer paid a settlement to the accuser. Other accusers apparently wait in the wings, weighing going public.

At a minimum, as a candidate heretofore admired for his candor, Herman Cain will be better served by inviting those who believe they were wronged by him to step forward and give him an opportunity to confront them. Otherwise, his unanticipated bubble of public appeal could pop in his face, along with his widely challenged 9-9-9 scheme for tax reform.

Jules Witcover is a syndicated columnist and former longtime writer for The Baltimore Sun. His email is juleswitcover@comcast.net.