It is possible more revelations will emerge and torpedo his candidacy, but so far the scandal has done little if anything to dent the enduring appeal of the former CEO of Godfather's Pizza.
Cain, a 65-year-old radio host from Georgia who has never before held elected office and is vying to become the first ever African-American presidential nominee for the Republican Party, continues to defy the odds.
Recent opinion polls have him holding firm alongside former Massachusetts governor Mitt Romney, the default front-runner for the Republican nomination. Texas Governor Rick Perry is polling a distant third.
After a congenial debate-style event with former speaker of the House of Representatives Newt Gingrich on Saturday evening, Cain made it clear he wants to move on and doesn't intend to keep fielding questions about the scandal.
"Don't even go there," he warned a reporter. "No. End of story. Back on message. Read all of the other accounts, where everything has been answered. End of story."
Washington news website Politico broke the story last Sunday that two women had complained of sexual harassment at the hands of Cain when he was head of the National Restaurant Association in the late 1990s.
One accuser, who received a settlement reportedly worth $45,000, issued a statement on Friday through her lawyer saying Cain had made a "series of inappropriate behaviors and unwanted advances."
Despite being released from the confidentiality clause in her original settlement, the woman, now a government employee, said she wished to remain a private citizen and would not be divulging any further details.
Cain belatedly conceded that he was aware that a female employee at the association had received a paid settlement. He denied any knowledge of a second alleged case and maintains he is completely innocent.
The Cain campaign has boasted that it is raking in more campaign contributions than ever despite the scandal and pundits agree that he appears to have weathered the storm.
"So long as we don't see more damaging facts come out, this is not the issue that's going to decide the election," conservative commentator Liz Cheney, daughter of former vice president Dick Cheney, told CBS's "Face the Nation" program.
An ABC News/Washington Post poll, conducted after the harassment allegations surfaced, showed Cain up from a month earlier with the support of 23 percent of Republican voters. Romney led the poll with 24 percent.
Leading Republican Senator Kay Bailey Hutchison said the charges were par for the course in the gloves-off political season.
"I kind of think that this is a presidential campaign thing where his opponents are coming forward and trying to dredge things up," she told CNN's "State of the Union" program. "I think it is politics as usual."
Gary Bauer, a longtime conservative activist who heads the American Values non-profit group, told CNN that the charges had not been backed up well enough to sway his opinion.
"We don't know exactly what he's allegedly done. And we don't have the names of any accusers, so I'm not surprised at all that it hasn't moved his support -- and it certainly hasn't changed my opinion of him."
Conservative pundit Bill Kristol predicted on Fox News Sunday that quite apart form the sexual harassment charges "the air is slowly going to go out of the Herman Cain bubble."
With the Republican primaries -- the state by state voting battles that decide the nominee -- just around the corner in January, voters will begin to reflect more seriously on what they're looking for in a president and who has the best chance of defeating Barack Obama in November 2012, he said.