The arc of the press reaction to these episodes echoes the acts themselves - first comes the fun, then the regret.

The fun is self-evident, and the story of the Louisiana senator is especially delectable: the sanctimonious family-values politician caught with his hypocrisy showing. Vitter - the man who called for President Bill Clinton to resign because he was "morally unfit to govern" - was back at work Tuesday, a week after he was linked to a Washington escort service.

The regret, this time around, has been expressed by two of my fellow columnists, E.J. Dionne Jr. and David Ignatius.

Dionne offered a "qualified defense" of Vitter. A "big part of me is rooting for Vitter to survive because I so want to return to a time when we ... chose to pay little attention to the extracurricular sexual activities of our politicians," he wrote.

Ignatius followed with a musing about the sadly diminished right to privacy. "Well, fine, you say, Vitter is a noisy 'family values' conservative, who should be indicted for hypocrisy if nothing else," he wrote. "But what about the thousands of other people whose phone numbers are on the D.C. Madam's call list?" he asked. "Are they fair game?"

My colleagues left out one key fact: This isn't just a moral transgression. If Vitter cheated on his wife, that would be a private matter of seeking, as he put it, "forgiveness from God and my wife."

But Vitter didn't just cop to a "very serious sin." It's a fair inference that he committed a crime. Deborah Jeane Palfrey, the "D.C. Madam" in whose phone records Vitter's number turned up, is facing federal charges of running a prostitution ring.

Do my colleagues bemoaning the loss of privacy think those charges should be dropped? Dionne says we should "grant Vitter our collective absolution and move on." Does he want to do the same for Palfrey? What makes Palfrey "fair game" for prosecutors, in Ignatius' words, but puts her client list off-limits?

Perhaps my colleagues are sexual supply-siders, uninterested in the demand part of the prostitution equation.

U.S. District Judge Gladys Kessler got the point when she allowed Palfrey to make her phone records public. Kessler wondered why prosecutors "exhibited such a strong interest in protecting a list containing the telephone numbers of unindicted co-conspirators."

There is a huge difference, one that seems to have gotten lost in all the Vitter discussion, between having extramarital sex and paying for it. I'm not in any way condoning the former, but I have a much bigger problem with the latter.

Put it this way: I would sooner vote for a politician who cheated on his spouse than for one who went to a prostitute. One is demeaning to a particular woman, the second to all women.

For some people, adultery itself is disqualifying in a politician. I think marriage is too mysterious an enterprise to go that far. It's hard to know - and therefore impossible to judge - what happens inside someone else's marriage. People stray; spouses forgive, or not; that's their business. But paying for sex, in whatever form, is both illegal and repulsive. It reveals a view of women as commodities that is relevant to lawmakers' public responsibilities.

There is, I think, a men-are-from-Mars aspect to this discussion. Men, at least some men, tend to think of purchased sex - even if they would never think of purchasing sex themselves - as less offensive. It's more transactional, less emotional, therefore - supposedly - less troubling.

"But, honey, she didn't mean anything to me."

That excuse might make Mrs. Vitter feel better about Mr. Vitter, though I wouldn't bet on it from her previous comments, likening herself more to Lorena Bobbitt than to Hillary Clinton. It doesn't make me feel better about Senator Vitter.

You could argue that prostitution should be legal in this country, as it is in many others - that America should get over its hang-ups about sex and that regulating prostitution would protect women from being victimized. I don't buy that, and in any event, I don't see my privacy-advocate colleagues making that case.

One man who has understood the importance of dealing with the demand side is former New York mayor Rudy Giuliani, who went after prostitution in the city by targeting customers as well as prostitutes. Under "Operation Losing Proposition," Giuliani's police arrested johns and confiscated their cars. He didn't wring his hands over their lost privacy.

So what does Candidate Giuliani say now - now that his own marital missteps are campaign fodder, and his southern regional chairman is David Vitter? At a town meeting in New Hampshire last week, Giuliani sounded like my fellow columnists. "I believe," he said, "it's a personal issue." --- Marcus is a member of The Washington Post's editorial page staff.