Seth Godin hits it on the head:
“Attack ads don’t always work. There’s a reason most product marketers don’t use attack ads. All they do is suppress sales of your opponent, they don’t help you. Since TV ads began, voter turnout has progressively decreased. That’s because the goal of attack ads is to keep your opponent’s voters from showing up. Both sides work to whittle down the other. In a winner-take-all game like a political election, this strategy is fine if it works. So why didn’t the ads work this time? The tribe that Obama built identified with him. Attacking him was like attacking them. They took it personally, and their outrage led to more donations and bigger turnout. This is the lucky situation Apple finds itself in as well. Attacking an Apple product is like attacking an Apple user.”Or more succinctly–attacking a cult leader simply enrages his followers.
As usual, the Obama campaign understood this principle.
Obama ran attack ads going after McCain (whose supporters didn’t particularly like him), not against Palin (who was beloved by her base), even though he had far more damaging ammunition when it came to Palin.
Alas, the converse implication is not that “attack ads no longer work,” but rather “attack ads don’t work against a passionate following,” so don’t expect the 2008 elections to mark a sudden turn to civility in American politics.