Forget "bitter"; Obama must believe that most Americans suffer from an attention-deficit disorder so crippling that they can't concentrate on their own interests or values.
Obama has an acute self-interest in so diagnosing the American electorate. His campaign knows he's vulnerable to the charge of being an elitist liberal. Unable to argue the facts, it wants to argue the law -- defining his weaknesses as off-limits.
Here are the Obama rules in detail: He can't be called a "liberal" ("the same names and labels they pin on everyone," as Obama puts it); his toughness on the war on terror can't be questioned ("attempts to play on our fears"); his extreme positions on social issues can't be exposed ("the same efforts to distract us from the issues that affect our lives" and "turn us against each other"); and his Chicago background too is off-limits ("pouncing on every gaffe and association and fake controversy"). Besides that, it should be a freewheeling and spirited campaign.