Since Sarah Palin won't rule out running for the presidency in 2012, her performance recently at the Tea Party convention in Nashville deserves more scrutiny. Voters may have to soon evaluate her as a future leader of our nation and defender of the free world. Which makes her strikingly vapid answers to the softball questions thrown her way all the more frightening. When Palin barnstormed the country as Sen. John McCain's running mate, she had a glaring lack of comprehension of national issues. But then, she had a lot to learn in a short time. By now she should be...