Herman Cain in Washington earlier this month. (Chip Somodevilla/Getty Images)

An affair to forget? That’s the question for voters as Herman Cain reconsiders his presidential bid after allegations of a 13-year affair. He denies it; his lawyer deemed it “alleged consensual conduct between adults” — a private matter and no business of the media or the public. As of press time, he’s still in the race.

Are affairs the new divorce? As in, once an automatic deal-breaker for pols, but no longer?

“We’re about to learn if the shock value of adultery has worn off,” Democratic political strategist Donna Brazile told us Tuesday. “It’s either going to wash off or it will stick. If it sticks, it means we believe our presidents should be held to a higher moral standard.”

Newt and Callista Gingrich in Florida last week. (Spencer Platt/Getty Images)

It doesn’t seem to be an issue for fellow Republican presidential candidate Newt Gingrich or Bill Clinton, who both bounced back from very public extramarital relationships. But adultery ended the public careers of John Edwards and Mark Sanford. And Cain? Former presidential candidate Mike Huckabee told Fox News the news is “the most damaging allegation that has been made to date” for him.

Divorce was a serious blot on the early aspirations of Ronald Reagan, and Nelson Rockefeller lost his bid for the 1964 Republican ticket after his roundly condemned divorce and remarriage to a young woman, herself divorced.

Ronald Reagan at his 1952 wedding to the former Nancy Davis. He’s the only divorced man elected president so far. (AP)

“It’s not that we’re immune to it — we process it differently now,” said Democratic consultant Joe Trippi. Clinton probably wouldn’t have been elected in 1992 if Gary Hart hadn’t fooled around five years earlier. “People’s first reaction was, ‘We should get rid of this guy,’ ” Trippi said. “The second was, ‘He had some really good ideas. Maybe we should have thought about it more.’ ”

Most voters, said GOP strategist Mike Murphy, are more interested in things other than affairs. “It helps to be well known and well thought of in other areas so the affair is seen as a distraction to bigger political issues that voters are far more concerned about,” he told us.

Bill and Hillary Clinton discussing their marriage on “60 Minutes” in 1992. (AP)

Brazile thinks Cain’s campaign is damaged — “I don’t think we’ve crossed the line where we totally dismiss allegations of adultery” — but that he’ll stay in the race. “My gut tells me that Herman Cain is not done.”

Read earlier political sex scandal coverage:

Rita Jenrette’s new take on an old sex scandal, 11/28/11

Political sex scandals: Who survives, who crashes and burns, 6/5/11

Political wives increasingly skip the confessional press conference, 6/6/11

Chris Lee and the anonymity of the average pol, 2/14/11