EVER since Abraham Lincoln made a virtue of log cabins, crafting the right autobiography has been an essential task for anyone seeking high office in America. On Monday November 16th Sarah Palin, ex-governor of Alaska and failed vice-presidential candidate in 2008, made an eagerly awaited appearance on the Oprah Winfrey show, as part of the launch of her biography. That book, “Going Rogue”, is already topping the bestseller charts, as readers rush to read about gossip and infighting during last year’s presidential campaign and to size up Mrs Palin herself.