Alaska Gov. Sarah Palin offers a sobering variation on the Peter Principle -- the idea that because talented people are usually promoted, they "rise to the level of their incompetence." Most people, if they keep going up, eventually reach a level where they can't cut it. Palin was clearly not qualified to be president, which is why picking her for vice president was such a bad decision on John McCain's part. But it was her exposure as a vice presidential candidate that ultimately showed Palin's inability to thrive as a governor. Palin's resignation statement lies so far outside the normal metrics of political calculus that it's already inspired reams of speculation about her "real" motivation. Did she make the mistaken bet that this would position her better for a presidential run, etc. I'm certainly in the camp that this deals the mortal blow to any further national aspirations she may have entertained. But I'm going to take her at her word -- she felt like her family was suffering in the spotlight and that, once she declared her a lame duck, the job wasn't worth having. On its face, that's a bad call. Her family has decided, Palin proudly notes, that it was time to get out of the gubernatorial kitchen. I don't want to question what anyone does for the sake of her family but would only recall that she didn't seem to worry about her young family's possible concerns -- her newborn son, her pregnant teenage daughter -- when she "unblinkingly" accepted the VP nod last year. But more to the point, she has an entire legislative session to go. Her strength as governor was largely in knowing how to push her advantages as far as she could and also how to play the media -- at least, before her vice presidential run. With oil prices heading back up, there were certainly some pet initiatives she could have pushed -- or further "permanent fund" refunds she could have secured for her citizens. But aside from guessing what she might have done in Juneau, certainly being governor -- and the country's most famous governor, outside of Arnold Schwarzenegger, at that -- provided her with a better platform to push her views on energy and national security, as she says she intends to do, than any TV gig or whatever else she decides to pursue next. Simply on principle, however, this decision is an insult. The argument about another Republican governor resigning turns on the question of whether he has become too great an embarrassment to the state, but it's also about the need for leadership for South Carolina. No one says, well, Sanford's only got 18 months left, it doesn't really matter at this point. And what about all those other lame-duck governors? Nearly every state limits its governor to two terms. Should we expect mass resignations at the end of each governor's seventh legislation session? "You take it from here, boys -- I just don't have it in me to play this out." Being a governor of a state is a serious job, one that at its quietest requires constant political decision-making and a stickler for management. Palin had always brilliantly exploited every opportunity that came her way. But she has now blown the great opportunity that was already hers, which is why even supporters have turned so hard against her over the last 24 hours.