Yes, that's right, I'm going to defend hypocrisy.
A lot of otherwise nonjudgmental people seem very quick to throw out this particular accusation. Nobody likes a hypocrite, but why? I think it's time to challenge some assumptions.
The first problem with calling people out on hypocrisy is that we're all hypocrites (for example: I have in the past and probably will in the future call people out for hypocrisy). Many of us have at least a few strong ideals that we will share with other people from time to time, but we're all of us imperfect, human: we don't always live up to our values, although we're very good at making excuses for ourselves when we fail.
There's been some social scientific research on hypocrisy, but I don't feel like looking it up and you probably don't feel like reading it. Suffice to say, from what I have perused, there's evidence (surprise, surprise!) that hypocrisy is quite common, for just about everyone. But we all know this, anyway, from experience, so I'll move on.
At this point you may object: "Sure, we're all hypocrites sometimes, but some are bigger than others. Nobody listens to me, but public figures can have a lot of influence on other people, and there's nothing worse than them telling others not to do things that they themselves do."
My response to this brings me to my second point. Sometimes it's okay to hold different people by different standards. (In fact, the very objection hypothetically posed presupposes that public figures be held to a different standard than private citizens.)
Take Al Gore as an example. He travels around the world a lot, doing his slideshow and so forth, to try to convince people of the enormity of human-caused global warming and to inspire them to take action against it. Since he doesn't have a magical zero-emissions jet, his carbon footprint is rather considerable.
Now let's pretend (counterfactually; in truth, Gore spends large amounts of money to offset his carbon footprint) that he ignored this fact and continued to do his slideshow all over the world. Has our hypothetical Gore lost all credibility because he's a hypocrite?
In a world of black-and-white morals (like Tennessee, perhaps), that might be the case. I don't know how many times I've heard arguments to this effect: "Don't trust Noam Chomsky; he hasn't given up all his positions to go live on an anarchosyndicalist commune!" But in the real world, sometimes you have to do things you don't approve of in order to accomplish things you value more. Gore has changed so many other people's behavior that his effect will be a net positive regardless of what he does.
Take another, less controversial example. Let's say that you really support candidate X or proposition Y and spend large amounts of effort, time, and money to convince people to vote for him/her/it. Voting day comes around, and you suffer a lapse of energy, deciding to stay home instead of going out to the polls. As it happens, the race is close (say 100 votes), but your desired outcome is achieved. (Elections are almost never decided by a single vote.) Would you be a hypocrite in this case? In a sense, yes, but you still achieved more good than if you had merely voted without campaigning. (In presidential elections, this is more excusable for people who don't live in swing states.)
In short, people's circumstances often differ. We live in an egalitarian-minded society, but few ethical rules can be applied uniformly without consideration for the situation. When the actions of a mass of people easily outweigh those of an individual, hypocrisy isn't all that bad (except to the extent that it does in fact undermine your credibility, reducing your potential impact).
Third, and finally, accusations of hypocrisy are often leveled as excuses for one's own questionable behavior. In logic, there is a seldom invoked fallacy called "tu quoque", which is just Latin for "you too", that applies to charges of hypocrisy. It's an instance of ad hominem, in which you attack the speaker rather than what s/he says. Wikipedia has a decent article on it, so let me copy their formulation. The following argument is invalid:
A makes criticism P.
A is guilty of P.
Therefore, P is dismissed.
I see this a ton on political blogs. "The Republicans are telling us not to use 527s to smear them? But what about the Swiftboat Vets, etc.? If they can do it, we certainly can too!" This is one reason the high road is seldom taken in politics.
But you can see how easily this can be used to rationalize a person's behavior. In the previous example, if dirty politics is wrong in one case, then it's still wrong for you to do it even if your opponent does it and at the same time says not to do it. It may make it easier on your conscience, but just because large numbers of people do something does not make it right. (Two wrongs don't make a right, as it is often said but seldom practiced. :-) )
In this case, in fact, the accusers are being doubly hypocritical. First, for trying to justify their use of practice Z, which they otherwise say is wrong, and second, for accusing another person of being a hypocrite while themselves being hypocritical ("meta-hypocrisy" you might call it).
Look what has happened here, though. In all the accusations back and forth of hypocrisy, the real moral issues at stake have been lost sight of. Instead of discussing the appropriateness of policy T, we end up discussing whether minor infraction U counts as a violation of principle V, thereby making actor W a hypocrite. While these kinds of social games may be fun (and increase TV ratings), they are totally counterproductive.
So the next time you feel the urge to accuse someone of hypocrisy, stop a moment and think if it really matters. (Just because everyone else likes to yell "hypocrite!"--including me, at least sometimes--doesn't make it right, after all.) If it's an issue that you care about, playing the hypocrisy game will be self-defeating. More likely than not it will serve as a distraction, leaving the undesirable status quo in place. Why not just focus on what's objectionable about the policy position, behavior, or whatever, that's in question?