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.
Yet unpublished estimates of how many people are seeing the ads, based on Nielsen ratings, show that over all, neither side has been getting into significantly more homes.
In Ohio, Iowa and Wisconsin, for example, Republicans have put down considerably higher amounts in local television markets — sometimes by a 3-to-2 margin. But that spending did not translate into a commensurate advantage with viewers, audience data available to the presidential campaigns showed.
In Florida and New Hampshire, in fact, pro-Obama ads have been reaching considerably more people, the data showed.
But Mr. Romney and his supporters have started to buy more advertising time. And with eight days until the election, there is still plenty of time for them to increase their engagement.
But Mr. Obama has been helped by a structural advantage, stemming from differences in the ways he, Mr. Romney and their allies have built their war chests. Both men are on track to raise $1 billion along with their parties this election cycle, with much of the money budgeted for advertising. And when the super PACs are included, the final tally will include hundreds of millions of dollars more, most of that benefiting Republicans. Mr. Romney has raised a much larger proportion of his money to date for the Republican National Committee.
But Mr. Obama and the Democrats, buoyed by millions of small donors, have raised a vast majority of his cash directly for his campaign committee, which under federal law is entitled to preferential ad rates over political parties and super PACs.
On the Republican side, super PAC spending has been a far greater necessity because of the Romney campaign's cash shortages over the summer. More than half of pro-Romney advertising spending to date has come from super PACs, which sometimes pay double and triple what candidates pay for TV time.
For example, in Florida over the last month, both sides reserved roughly the same amount of time — at $25 million each. But the audience reach of the pro-Obama ads was far greater, sometimes by 20 percent, audience data showed.
The Obama campaign believes that the differences between its advertising strategy and the Republicans' efforts, which are more disjointed, are helpful in other ways. First, it can control almost all of the advertising placement and timing itself. Second, though it has benefited greatly from more than $100 million in advertising from its super PAC, the Obama campaign has not had to rely nearly as heavily on outside groups, which campaigns are prohibited by law from coordinating with.
"It's nice to control your own destiny," said Larry Grisolano, the director of paid media for the Obama campaign.
That is not to say that the Obama strategy is not without inefficiencies or unexpected expense. In fact, the campaign said it had spent more in the last three weeks than it initially budgeted.
Even the best-laid plans are at the mercy of this year's erratic market, in which an ad during the "Today" show in Norfolk, Va., an important region with a population of 242,000 in a battleground state, can cost nearly three and a half times as much as an ad in the same time slot in New York City, where there is little demand for political advertising time.
The lowest rate federal candidates are entitled to is breaking records this year because of surging demand. "A rising tide floats all boats higher," said Will Feltus, senior vice president of National Media, which buys advertising time. "But this year it's like a tidal wave."
Mr. Romney's media buying is less susceptible to the wild swings of the market because it waits until the last minute before reserving its commercial time. This means it pays higher rates, but it is also not running into what has become a significant problem for political advertisers this year: getting bumped by someone offering to pay a higher price.
The New York Times examined files of the Cleveland NBC station, WKYC, in one of the most saturated media markets this year, and sometimes found price increases of three- or fourfold. For the week of Oct. 8, the Obama campaign put down an advance purchase order on the "Today" show for $400 per 30-second spot.
But super PACs like the conservative group American Crossroads, which paid $2,500 for the same spot on "Today," had bid the price up so much that the Obama campaign ultimately ended up paying $1,400 for each ad. The Romney campaign, which had reserved its time only the week before, also paid $1,400.
The Obama campaign has expressed alarm about scenarios like this, warning that its resources could fall short in the final days of the race. In an e-mail to supporters on Friday, Jim Messina, the campaign manager, wrote that Republicans "can outspend us by $4 million per day, every day, for the final 11 days."
Some advocates of campaign finance reform are concerned that because an onslaught of ads has failed to bury the president as expected, their own efforts might be stymied.
"There's a worry that if there's parity in terms of spending on ads, that it will diminish the appetite for reform," said Ellen Miller, the executive director of the Sunlight Foundation, which monitors outside spending.
"But this is not about whether the candidates can game the system," she added. "It's about whether Americans can be fairly represented in a democracy that depends on big money, much of it spent in secret."