Chris Cillizza has the details:

Barack Obama is outspending John McCain at nearly a three-to-one clip on television time in the final weeks of the presidential election, according to ad buy information obtained by The Fix, a financial edge that is almost certainly contributing to the momentum for the Illinois senator in key battleground states.

From Sept. 30 to Oct. 6, Obama spent more than $20 million on television ads in 17 states including more than $3 million in Pennsylvania and more than $2 million each in Florida, Michigan and Pennsylvania. McCain in that same time frame spent just $7.2 million in 14 states. Even when the Republican National Committee's independent expenditure spending in Indiana, Michigan, Ohio, Pennsylvania, Virginia and Wisconsin is factored in (a total of $5.3 million), Obama still outspent the combined GOP forces by roughly $8 million in the last week alone.

There had been concern for a time that Barack Obama's fundraising juggernaut might not be enough for the combined fundraising might of the McCain campaign and the Republican National Committee -- the two of which, along with assorted state parties, could reap campaign contributions approaching $100,000 in size -- but this report from Cillizza should help assuage such worries. The fact that the Obama campaign is still advertising in 17 states -- not 8 or 11, but a 17 -- says a great deal. Obama still has a sizable 60 percent plus edge in ad spending even considering RNC independent expenditures. With McCain's negatives already on the rise and the political environment clearly favoring the Democrats, it's going to be awfully difficult for the GOP nominee to claw his way back in this with significantly less money to spend than his Democratic rival.