What does it say about the Republicans - and about mainstream American culture - that so many current and potential GOP presidential candidates have track records as party animals?

Not so long ago, the folks who marketed themselves as exemplars of traditional "family values" were insisting that President Clinton should be thrown out of office for lying about his personal peccadilloes. Yet today, these same folks have anointed, as their front-runner, a thrice-married former mayor whose kids barely speak to him. And Rudy Giuliani's chief challenger is John McCain, a self-confessed youthful philanderer who courted his future second wife while still married to his first, then launched his political career with his second wife's money.

A lot of conservatives don't like the top two - yet that's because they distrust Giuliani and McCain on the issues, not because both men have engaged in libertine behavior. And consider the personal histories of the conservatives' dream candidates:

Fred Thompson is now married for the second time, to a woman 25 years his junior, and has boasted of his wild 'n' crazy phase between marriages ("A lot of women chased me, and those that chased me tended to catch me").

And the other dream candidate is Newt Gingrich, who is now on his third marriage, and who famously cheated on his second wife while leading the impeachment crusade against Clinton. Wait, perhaps this item is more noteworthy: Newt served divorce papers on his first wife as she lay in a hospital bed recovering from cancer surgery.

Right now, according to the latest Harris poll, those four guys are the top choices of likely Republican primary voters. It's the Mr. Clean guy, the one who's still married to his first wife, the guy who puts his 10 grandchildren into his campaign literature, who's stuck in fifth place. Such is Mitt Romney's predicament, in a year when even James Dobson, the religious-right power broker, can decree on his Christian radio show that he has prayed with Newt and that he has no moral qualms about Newt.

Clearly, there has been a sea change in the public mood. Having a zipper problem, by itself, is no longer deemed to be a serious disqualifier, even within the GOP camp. Candidates with indulgent personal histories probably can thank Clinton for this. Americans endured the Monica Lewinsky scandal, and when it was over, they rendered a split verdict. They told pollsters in 1999 that Clinton was a man of disreputable personal character - but they thought that he was doing his job well, and therefore that he should remain in office. Americans drew a sharp distinction between private and public virtue, and that seems to be the operative ethos today.

Twenty years ago this month, America was rocked by the Gary Hart sex scandal. The media discovered that the married Democratic front-runner was keeping company with a model named Donna Rice, and this news ultimately sank his candidacy. A long controversy ensued over whether journalists should have chased that story, but today the issue is settled. Journalists (joined by bloggers) basically root out whatever they can - New York magazine has been digging into the third Mrs. Giuliani's divorce papers from her first marriage - and most people either ignore this stuff or weigh everything case by case.

However, I'm not suggesting that we've suddenly become French. In true Gallic fashion last week, French voters elected a new president, Nicolas Sarkozy, while shrugging off the news that his wife, Celia, had flown to New York with her lover, just two years ago, after complaining that Nicolas had been treating her as "part of the furniture." Nor did they care that Nicolas slept with a French political journalist during Celia's absence. It's hard to imagine an American candidate and spouse getting off so easy; at the least, many in the American pundit class would question their "character" and "judgment."

Indeed, some religious conservatives still insist that private and public behavior are synonymous and that candidates should be judged accordingly. Richard Land, an influential leader who runs the Southern Baptist Convention, was dissing Giuliani on Fox News the other day when he said: "If a man will be dishonest to his wife, he'll be dishonest with anybody." Land was referring, in part, to the fact that Rudy's second wife didn't know she was kaput until she heard her husband announce it at a news conference.

And one GOP presidential candidate, ex-Arkansas Gov. Mike Huckabee (a onetime Baptist minister), said earlier this month: "If I fail to keep the promises I made to the people closest to me, then I'm not sure how reliable I'm going to be in keeping promises to total strangers who vote for me." He also urged evangelical Christians to judge all candidates with the same moral yardsticks they used on Clinton. Yet, if his argument was having any traction, he'd be gaining ground with the total strangers. He is not.

Perhaps sex and marriage issues simply seem unimportant on the eve of such a consequential election; after all, we're poised to pick the first new president since 9/11, and it's fair to suggest that we care less about a candidate's marriage vows than his or her vows to keep us safe. Certainly, this is Giuliani's calculation. As he said on Fox News the other day, "I'm willing to rest on my job performance. . . . I can perform under pressure, and I can perform irrespective of the fact that I do make mistakes in my personal life."

But we're also more willing to cut candidates some slack on their personal lives - in part because we are far less willing than ever to idealize the institution of marriage. The latest federal health statistics bear this out. The marriage rate - marriages per 1,000 people - has dropped nearly 30 percent during the last quarter-century; the number of cohabitating couples has jumped tenfold since 1960. (The divorce rate has dropped as well, but, at least in part, that's because there are fewer marriages than previously.) In other words, when judging the private lives of politicians, there is no longer a consensus Ozzie-and-Harriet standard.

There is, however, a desire to weigh each case on its merits. Adultery and divorce may not be automatic disqualifiers, but the specifics might be deal-breakers. A candidate who divorces amicably, and remains close to the kids, might be fine. A candidate who publicly humiliates a soon-to-be ex-spouse, and hurts his relations with the kids, might be more problematic, particularly if that behavior seems to suggest a broader pattern of arrogance. Giuliani fits the latter profile - his own daughter reportedly didn't bother telling Dad about her recent acceptance to Harvard - which is why he hasn't necessarily closed the deal yet with the primary electorate.

Still, the fact that he tops the GOP field tells us plenty about our post-Clinton mores. As one prominent Washingtonian remarked at a political conference, one year after the impeachment trial: "Maybe we expect too much [of a president]. Each of us is only human, with our own foibles and shortcomings."

Thus spoke Kenneth Starr, the prosecutor who had dogged Clinton in the Lewinsky scandal. Really. I was there, and I heard him say it.

Contact Dick Polman at dpolman@phillynews.com.

See his blog at http://go.philly.com/polman.

His blog is excerpted on the Tuesday Commentary Page.