To understand why Katie Couric's interviews with Sarah Palin so effectively exposed the Alaska governor's unpreparedness for high office, one must first understand the special powers of Popular Girls.

First, let's define our terms: Popular Girls are those girls all of us knew in school, even if only from afar. They possess a special aura, a preternatural confidence, an instinct for when to let others in, and when to shut them out. Of course they rarely need to proactively shut out others because those who are not wanted rarely try to enter. They are sometimes terrifying, but also thrilling: somehow they were chosen, predestined to rule. And they make it look so easy -- floating through the halls, finding each other (they share the same frequency), then laying claim to prime territory in the cafeteria.

Contrary to, er, popular belief, "Popular Girls" are not interchangeable with "Mean Girls." While most Mean Girls are indeed high-status, they are simply a subset of Popular Girls -- Popular Girls who have chosen to use their power for evil.

The most popular of Popular Girls at my elementary school was Missy Golden. She always had the best clothes and a great tan, and she was really good at gymnastics. But she was also really nice, a benevolent Popular Girl. And so niceness prevailed among her subjects. Because of Missy, I attended a kinder, gentler Wood Acres Elementary.

Mean or not, Popular Girls possess extraordinary perspicacity. They have a way of stripping you bare, finding you out. Masters of persuasion themselves, it's impossible for others to fool them. And if you cross them in any way, they can be ruthless. I'm convinced that it will be a Popular Girl who finds Osama bin Laden ... and kills him (unless of course, he's being guarded by Popular Girls).

Both Sarah Palin and Katie Couric were Popular Girls. They understand each other -- and this is where Palin miscalculated. Sarah knew that she would be unable to flirt with Katie as she has with her male interviewers (all three of them!). This was always going to be a minus.

But she presumed that Couric would honor the Popular Girl Pact and keep things easy -- maybe chat about "balancing work and family!" or kibbitz about "keeping in shape with a full-time job!"

Sadly for Palin, Katie never signed that Pact. From the start of the first interview it was clear that Katie's Popular Girl powers would serve a higher calling: she was determined to get answers to questions that matter -- not showboating gotcha questions, but questions that would give her audience the means to evaluate Palin's fitness for office, good or bad. In other words, Katie was there to do her job.

Palin was thrown. She could have gone sassy ... but that would never have worked. (Sarah might have been queen of her cafeteria back in Wasilla. But Katie's cafeteria was a helluva lot bigger.) Instead she had no choice but to nakedly face Katie's questions. No recourse to cutesy, no detour to folksy. Just questions and answers, unadorned with theatrics. In the process Sarah unwittingly revealed that she's not only misinformed about the world outside Alaska. She's uninformed. (Actually it was worse than that. Can you be deinformed or exinformed?)

Part of what so fascinating was how Sarah became so transparently desperate for Katie's approval, the beta to Couric's alpha. (Popular Girl dynamics are a whole field of study.) But Katie was not there to approve or disapprove.

As I've written before, my hope is that Katie and Sarah will continue their interviews after the election, even if Obama-Biden wins, on a whole range of topics. I can just hear the exchange about Bristol Palin's baby shower:

Katie: Governor Palin, what are you planning to serve at Bristol's baby shower?
Sarah: Well, Katie, we thought we'd serve a Waldorf Salad.
Katie: Why not a Cobb Salad?
Sarah (after a beat): We're also going to have quiche-
Katie: Governor Palin-
Sarah: And some fresh peach pie-
Katie: Governor Palin, why not a Cobb Salad?
Sarah (desperately): Maybe a watermelon lemonade-
Katie: Governor Palin, why not-
Sarah (finally breaking): Katie! Why are you always trying to undermine me?!

Palin has regained some ground with her debate performance, shamelessly flirting wtih both Joe Biden and America. But ill-advisedly Sarah has complained to Fox News that Katie's interview "annoyed" her. Ouch, one Popular Girl trashing another behind her back. Sarah is so gonna get it!