It wasn't that long ago that Susan Rice was being painted as not only incompetent but a liar by Republican politicians and conservative pundits. Having thoroughly destroyed her reputation, some of these same voices are using her words to undermine the reputation of Hillary Clinton.
Notice what is occurring here. We have someone that we are told is absolutely unreliable—when her views are inconvenient—who can be absolutely trusted to give a correct characterization of another person we are not supposed to like, because now what she has to say is of use.
Similarly, there has been a recent explosion in the virtual world of rumors and stories about what is really behind the resignation of Benedict XVI. Many of these stories have been linked to and taken as gospel, though the rely on unnamed sources or even discuss the secret plans and actions of unnamed countries and made-up organizations like the International Tribunal into(?) Crimes of Church and State. These same people, all of them rational, some of them philosophers—people who get paid to be rational—would reject bald appeals to authority in almost every other context and would find appeals to unnamed authorities risible, if the topic were any other at all.
By the way, there is one lesson to be drawn from at least the last link above: calling oneself a tribunal and claiming that one's decisions supersede all national and international law, because one knows better is apparently the way justice is achieved these days, even if one throws around words like "genocide" with no sense of what they mean. And, then, some people will take one as some sort of authority.
This is nothing new, nor is it limited in scope. It is no different in kind than those religious believers who appeal to their often misguided understandings of the utterance of some physicist to support Creationism, but deny other things said by the same authority in the same breath.
Of course, appeals to authority are always suspect, but why do we so quickly accept them in some cases, while seeing them for what they are in other cases?
Like those people who are constantly looking for inspirational quotes from historical figures, whether the quotes can plausibly be attributed or not, even if their content is opposed to everything those figures actually believed, what we are doing is looking for support—any support whatsoever—for what we already believe.
We have a belief and that belief is essentially unquestionable for us. When we hear that someone else agrees, we increase the authority with which they are invested to exactly the degree we are in agreement, and then we use the authority with which we have invested them because of their agreement to reinforce our own beliefs. They count as authorities because we agree; and, because they are authorities we must be right to agree.
It doesn't matter what actual authority they do or do not have. It is no better and no different than arguing that something must be true because "they say."
There's nothing virtuous in this pattern of arguing. But it's one that is too tempting for most of us, no matter how rational we like to think we are.