Here's a prediction: Colin Powell is going to endorse Barack Obama. I'm not pulling this out of thin air. I'm basing my forecast on a series of phone calls that I received this week. I can't say who called me, but I can tell you one of the questions I was asked: "What do you think the reaction would be if former Secretary of State Colin Powell - a Republican - introduced Democrat Obama at his big acceptance speech at Mile High Stadium after being made the nominee?" My reply: "It would seal the deal. It would be the presidency."...