The McCain campaign has now shifted virtually 100 percent of his national ad spending into negative ads attacking Obama, a detailed breakdown of his ad buys reveals.
By contrast, the Obama campaign is devoting less than half of his spending on ads attacking McCain. More than half of its spending is going to a spot that doesn't once mention his foe.
I asked Evan Tracey -- who tracks national ad spending for the Campaign Media Analysis Group -- to detail the amounts each campaign is spending on specific different spots. The idea was to gauge the precise degree of the McCain campaign's shift into negative mode amid his slide in the polls, and determine whether the Obama camp was following suit.