The list of battleground states has exploded with one week before the election. Michigan, Pennsylvania, and Minnesota are suddenly receiving millions of dollars after most assumed they rested safely in Obama’s column. Many Obama fans are fretting and Romney fans are enthralled that they’re on the offensive. But interpreting ad spending is extraordinarily difficult in this election and these buys are insufficient to alter perceptions of the state of the race.

When Obama started spending money in Arizona and McCain embarked on a last ditch effort to take Pennsylvania four years ago, there was no room to misinterpret the behavior of the campaigns. There was a consensus that Obama held a large lead in the national popular vote and a strong advantage in states exceeding 270 Electoral Votes. But without clear context, changes in ad spending can almost always be interpreted in either direction. If one assumes that Obama maintains a lead in Ohio, Wisconsin, and Nevada, Romney’s effort to “expand the map” can easily be interpreted as a last-ditch effort to circumvent Obama’s so-called “firewall.” On the other hand, if one assumes that Romney holds a discernible lead in the national popular vote, then it seems reasonable to expect that Obama would be vulnerable in at least one of those Democratic-leaning states, whether or not the electoral map made it necessary for Romney to pursue new options at a late stage. Without more definitive polling, either interpretation is defensible. For what it's worth, the polls in Ohio suggest that Romney would be wise to investigate alternative paths to 270.

Interpreting ad spending is even more difficult when the campaigns and their allies possess unprecedented resources to air advertisements well past saturation levels. When a campaign possesses tremendous resources, it’s harder to judge their strategic decision-making. Strategy emerges when available means are matched with desired ends, and unlimited resources often result in a growing list of objectives. There’s a lot to be learned when finite resources force campaigns to make choices and focus on the most pivotal states. For instance, when Romney’s coffers were depleted after the GOP primary, their first ad buy only included North Carolina, Virginia, Ohio, and Iowa. In contrast, Obama’s initial buy in 2008 covered Alaska and North Dakota, states that he lost by double digits in an election he won by 7 points nationally.

This week, Team Romney is spending a whopping $82.9 million on television advertisements compared to the paltry $23.6 million that the Obama campaign spent over the final week of the 2008 election. Much of Romney’s spending is driven by GOP-aligned Super PACs like Restore Our Future and Crossroads and these Super PACs have intermittently aired advertisements for months in Michigan, Minnesota, Pennsylvania, and even New Mexico. With spending escalating over the final week of the campaign, GOP Super PAC buys have also surged in these “lean-blue” states. Today, the campaigns have largely done all they can to influence the outcome in a state like Ohio, where both sides are spending tens of millions of dollars. When Team Romney gains even more resources after Restore Our Future decides it has an extra $17 million to inject the presidential race, what does a large buy outside of the previous battlegrounds really say? There might be an alternative to “momentum” to explain why these states haven’t received attention from the campaigns until now: they’re not as competitive as the initial nine battleground states.

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The fact that Restore Our Future is driving spending increases, rather than the Romney campaign, casts a certain amount of doubt on the competitiveness of all three states. Regardless of whether Obama's up 1 or 3 in Ohio, Romney's electoral map isn't as pretty it should be, at least based on the national polls. If Romney had a truly credible route to victory in any of these states, as Eric Fehrnstrum suggested in Minnesota, it would be wildly negligent for the Romney campaign to embark on anything short of an all-out effort to claim a victory. And although the Obama campaign felt these states were close enough to justify defensive spending increases, they appear to agree that these states aren’t as competitive as the initial nine battlegrounds. Despite Obama's response, Team Romney is outspending the Obama campaign by 5-to-1 in Minnesota and Michigan. In Pennsylvania, the Obama campaign is only being outspent to 2.5-to-1, perhaps a sign that they take the threat moderately more seriously in the Keystone State. But the Obama campaign probably isn’t alarmed by the situation in Pennsylvania if they’re allowing Team Romney to outspend them by 2.5-to-1 over the final week of the campaign. With the polls showing Obama with a modest lead and nearly fifty percent of the vote in all three states, it’s not hard to see why.

The introduction of early voting turns a final wrench into the case for reading into ad spending. While sizable shares of the electorate have already cast their ballots in Ohio, Iowa, Nevada, Colorado, Florida, and North Carolina, few have cast ballots in Pennsylvania, Wisconsin, Michigan, and Minnesota. To the extent that the utility of ad spending in the traditional battleground states might be diminished by large shares of the electorate casting ballots or reducing uncertainty about the eventual outcome, more spending in states with less early voting would be easily justifiable.

It is possible that escalation on lean-Obama turf is a harbinger of a closer race than previous polls suggest. But increased spending isn’t a sufficient basis to assume that the race is any closer than the surveys suggest. The campaigns and their allied Super PACs possess tremendous resources and the battleground states have already reached saturation levels, making it more difficult to read into additional increases in spending.

If you want to understand the playing field, follow the polls and the candidates. Unlike unlimited Super PAC spending, there is only one President Obama and one Governor Romney. Even then, we would still struggle to distinguish “going on offense” from a “desperate” attempt to circumvent Obama’s firewall without a clearer polling picture. But at least we would know that the campaigns were making choices about which states mattered most to their paths to victory, not just finding the next best place to dump excess dollars now that swing voters in Ohio have been institutionalized after months of relentless advertising.