I have in the past been a skeptic of Sarah Palin. Not of her political talent, which is considerable, but of her grasp of – and even interest in – substantive policy issues. When she abruptly resigned the governorship of Alaska on July 3rd, I wondered if she simply hadn’t the stomach for national politics. And the rambling, disjointed speech she gave that day left me wondering if she even knew why she was making such a momentous and potentially career-crippling decision. But then a funny thing happened: In November, Mrs. Palin debuted her memoir “Going Rogue” with great sales,...