When Sarah Palin burst (is there any other verb that describes it?) onto the political scene, as John McCain's running mate in 2008, she was the little-known governor of Alaska. After a rousing speech at the Republican National Convention followed by an unfortunate litany of gaffes, it became obvious that many thought she was not ready to be a heartbeat away from a 72-year-old president. But that was then, when her family, or at least one pregnant teen-age daughter, overshadowed anything she had to say, which in itself may have been a blessing. Most talking heads and many Americans, it...