Maybe the “super PACs” were not so super after all.

Despite repeated warnings from President Obama and his party that a flood of unrestricted donations from conservatives to outside groups would swamp them, the White House and its allies are at least holding their own. Over the last month, the pro-Obama forces have run more ads and, more critically, have reached audiences in roughly the same numbers as Mitt Romney and the group of well-financed conservative super PACs working to elect him.

A review of data from the last 30 days from Kantar Media/CMAG, which tracks political ad placements, shows that 160,000 commercials supporting the president have run, compared with 140,000 for Mr. Romney. And the Obama campaign and its supporters have broadcast more ads during the morning news and prime-time periods when television viewership is highest.

Though the disparity has started to narrow somewhat over the last week, with Republicans gaining a decisive advantage in places like Cleveland and Des Moines, the story in battleground states has been the same for much of the last month: even at their most effective, the super PACs have helped Mr. Romney fight only to a draw.

The lack of a discernible Republican advantage is all the more surprising because Mr. Romney and conservatives have been spending more money. Over all, total Republican ad spending for the presidential campaign is about $500 million. Democrats have put in close to $400 million.