Last week, I voiced a little Super PAC skepticism: Given the declining marginal return that’s resulting from unprecedented ad spending and the inability to coordinate with candidates, Super PACs are limited in their ability to influence the presidential election. Still, you’d think that at least they can flood the airwaves with ads, in hopes that overwhelming the opposition will move the needle a bit, right?

As it turns out, they haven’t even been able to do that. Writing at the Huffington Post, Paul Blumenthal finds that in both Florida and Ohio — the two largest swing state media markets — the Obama campaign has significantly out-advertised Team Romney and associated Republican groups. In August, Obama ran 6,473 ads to Romney’s 3,281. This advantage expanded further in September, with 7,083 ads from the Obama campaign, to Romney’s 2,690. The fight is closer in Florida, but Obama still has the advantage: 10,860 for Obama to 7,861 for Romney.

There are a number of reasons for this. The joint Republican effort might have more overall cash than Democrats, but the Obama campaign has more money to spend than the Romney campaign does. The result is that Obama has more money than Romney does over which he has direct control. But not only that, the Post reports that he’s able to get better advertising rates because it’s coming from his coffers, and not the Democratic Party’s. Team Obama is able to get more advertising bang for its buck than either Romney or GOP-allied Super PACs, and has directed that advantage to key swing states.

I noted last week that ads were most effective in the final weeks of the campaign — In 2000, voters in swing states were more than twice as likely to see a pro-Bush ad as a pro-Gore ad. Political scientists estimate this cost Gore as many as 4 points among undecided voters.

Given Team Obama’s huge ad advantage over Mitt Romney — and the extent to which Republican Super PACs haven’t been able to make up the difference — this might happen again. After a year of Republican barking over the potency of its money advantage, this election year might end with a wave of pro-Obama advertisements. With Romney’s already-low favorability among the majority of Americans, this could compound the GOP’s nominee’s problems in the home stretch.

Jamelle Bouie is a staff writer at The American Prospect . You can find his blog here .