My interpretation of the woman who didn't want to know about Gary Hart's sex life is different from yours. I supposed not that she thought it politically relevant but that she thought it irrelevant yet found it impossible not to react to, from personal distaste. Avoiding exposure to what we know will lead us astray is a familiar technique--as when you ask your host to take away the peanuts. Presidential sex on television is like peanuts: irresistible, but it ruins your appetite for everything else. Such information is less prejudicial for a majority of the electorate than it was 10 years ago, but it is just as disruptive. Of course everyone homes in on it, as they would on group sex in the window of Saks Fifth Avenue. If it's only in the National Inquirer, most of us can ignore it, but when it's on the networks and the front page of the New York Times, day after day, ignoring it requires a conscious effort, like ignoring malicious gossip. The media have abandoned all pretense of decency, and the most charitable interpretation I can put on it is that they are all sanctimonious hypocrites out to make a buck.
Respecting the privacy of public figures doesn't just protect them from treatment to which no one should be subjected. More importantly, it reserves the public forum for conflicts that have to be addressed collectively and doesn't waste that scarce and valuable resource on fruitless personal exposure and the emotions it ignites. Privacy is not just a private but a public good, essential for the functioning of civilized institutions at every level. There is too much going on in the personal and inner lives of any collection of individuals to fit into the common space where they must interact. Whether we're at a dinner party or in a political campaign, we have to exclude most of it and rely on other participants to do the same, or we will find ourselves in the kind of mess now being produced by the undiapered infants in Washington.
To enlarge on "pathological communitarianism": The odd thing is that the current breakdown comes from ignoring something that is well understood at the level of political theory--the need to recognize pluralism and individual variation as a limit on the reach of collective authority into personal life. It is the hard-won insight of political liberalism that limited government is not only possible but also humane and stable. A functioning social order does not require the state to control every aspect of human life or to squeeze all individuals into a single virtuous mold. The attempt to use the state's monopoly of force for such an end results in oppression of the most awful kind, whether in the service of religious orthodoxy or New Socialist Man. That is now well understood by most of us. We recognize that some individual rights define the residual sovereignty of each individual over his own life, and limit the reach of legitimate encroachment by the state. But the analogous resistance to purely social control is just as important, and it seems to have been forgotten, in spite of the ringing admonitions of John Stuart Mill. Exposing private lives to public judgment, even without the backing of law, extends the writ of collective decision to a domain where it is not only unnecessary but also socially destructive.
This applies in spades to politicians, whose whole purpose in life is to be objects of collective choice. They shouldn't be judged as universal moral exemplars so long as they don't foolishly present themselves that way. There may be such a thing as "character" in public life, but when the term is used in current political discourse, it invariably refers to private conduct. My own experience is that people's professional competence, effectiveness, and judgment have no reliable correlation with their private probity, kindness, marital fidelity, spiritual refinement, etc. But this is based on direct observation of writers, theoreticians, and scholars, not politicians. Do you think political distinction is more inseparable from personal purity than other types of talent? I would be amazed if you said yes.
I'm glad if we are not so far apart on the privacy issue, but that should be compatible with our disagreeing sharply about what people should and shouldn't do. Disagreements over the standards of private virtue are so wide in our large and unruly culture that the potential for terrible divisions is great, and I give thanks every day that the republic is held together by a political system of extraordinary tensile strength that protects individual rights and minority opinion. I suspect that you and I feel very differently about those acts of the president that I think none of us should know about. One perennial problem of liberalism is to distinguish its defense of particular, unpopular values from its defense of the removal of disputes over certain of those values from the public arena. Liberals typically think, for example, that there is nothing wrong with homosexuality, but they also think that collective decisions about the rightness or wrongness of homosexuality should not govern individual conduct. It is the second claim that is important for the defense of privacy--in law, in the press, and in society--and it is independent of the first.
You close with a question, but in the nature of the case, you can't give me enough information about your censorious politician and his closet full of juicy skeletons to let me guess whether exposing him would exceed the limit of admissible retaliation. Let me ask you a question in return: Why don't the Democrats make an electoral issue out of the pollution of public space? Why don't Democratic candidates for Congress say, "If you want this inquisition to go on for the next two years, vote Republican Nov. 3"?