Almost four years ago, I was watching Sarah Palin rile up a Clearwater, Fla., crowd with anti-Obama broadsides when a spectator let loose a bloodcurdling cry of "kill him!" To his credit, John McCain realized the Obama hatred was getting out of hand, and a few days later, when a woman at one of his events called Obama an "Arab," McCain did one of the most honorable things in his political career. "No, ma'am," he said, taking the microphone from the woman and enduring some boos from supporters. "He's a decent, family-man citizen that I just happen to have disagreements...