Ace of Spades HQ has a great essay about double standards. It's one of those things where you read it and give yourself the old V-8 cranial percussion move along with a "Well, duh. Why didn't I say that?" It's just so obvious once it's been pointed out and Ace points it out perfectly. Here's a teaser:

1) In the beginning, the double-standard exists, but those who practice it are not really aware of it. People are always much more sensitive to unfairness towards they themselves than unfairness to other people. Those who practice double-standards initially are unconscious of them, as the unfairness falls to groups they are unsympathetic to.

2) After some time, the existence of the double-standard is brought to their attention. They ignore the charge, chielfly because the beneficiaries of the double-standard are groups or people they're sympathetic to, and those injured by the double-standard are people or groups they're hostile to. In their minds, no harm, no foul.

3) At some point, the existence of the double-standard is well-documented enough, and complained about loudly enough, that they can no longer simply ignore it. At this point, the practitioners of the double-standards simply begin lying. They claim there is no double-standard at all.

This, of course, is where most of the liberal media is right now, and in fact has been for 20 or 30 years.

4) Finally, the existence of the double-standard can no longer be denied with a straight face. At this point, rather than strive for fairness and the abolition of the double-standard, the proponents of the double-standard simply begin inventing reasons as to why the double-standard is necessary and justified and right.

Much more good stuff in the full article.