Kerry constantly changing his opinion or position is just a hype created by the Republicans. If you had carefully listened to everything he said (I watched all 3 presidential debates, the Democratic convention, etc.), he actually doesn't and is very consistent. But things aren't just black or white, and that is what simple people don't understand. And as the majority of Americans are simple-minded that acted in Bush's profit. That is surely the best explanation I can think of to explain the election's results.