This week, Sarah Palin stoked a late, brief flurry of speculation that she might enter the 2012 presidential race. I wont try to predict the former Alaska governor's decision. But I will predict this: If Palin does enter the race, she won't be any kind of factor. Over the past three years, Palin has systematically laid waste to the basis for a presidential campaign. By her own words and actions, she has discredited herself and alienated her one-time supporters. But before Palin vanishes into her hard-earned obscurity, Republicans need an assessment and an accounting. Had John McCain won in 2008,...