It's a battle for offense right now. Both campaigns lob bombs, hoping to make an impact and gain momentum. If something doesn't work, they try something else.
McCain's anti-Obama Paris Hilton ad in early August was a game-changer. It refocused the campaign. Everything was Paris Hilton.
The conventions gave momentum to both sides temporarily, and the Sarah Palin pick literally stopped the campaign for two full weeks.
Who's got the ball?
Who's on offense right now? Obama. The campaign is pressing hard on the economy. The Democrats have seized on McCain's "the economy is fundamentally strong" statement and are running with it. It got traction yesterday because of the Wall Street meltdown.