Much has been written about what Tuesday's Wisconsin recall race says about the influence of big money on politics, but the real story may be the influence of the money we don't know about.

Less than three hours after Democrat Tom Barrett conceded the $63 million-and-counting contest to Gov. Scott Walker, Americans for Prosperity, the big spending conservative group, sent an email to supporters hailing Walker's win and including a video highlight reel about "how AFP educated Wisconsin residents about Governor Walker's budget reforms."

The video shows footage of the customized AFP bus that rolled through the state during week before the election,  as well as green shirted AFP volunteers going door to door with the high tech tablets they used to track voter information. Several shots show them carrying door-hangers bearing the names of Walker and his lieutenant governor, Rebecca Kleefisch.

So how much has the AFP reported spending on the Wisconsin campaign?

According to Wisconsin's Government Accountability Board, the agency that tracks campaign expenditures in the state, nada. "AFP has not registered with us," reports Reid Magney, a spokesman for the GAB. 

Nor is it likely to do so. Americans for Prosperity, which reported revenues of $22 million in 2010, claims immunity from such paperwork because, it is a non-profit organization which, by its own description, is focused on issues, rather than advocating for or against a particular candidate.

"We're not dealing with any candidates, political parties or ongoing races," AFP's Wisconsin director, Luke Hilgemann, told an online news site in Wisconsin. "We're just educating folks on the importance of reforms."

AFP president Tim Phillips' election night email left little doubt as to whom the organization supports, however. "Remember when everyone said the sky would fall?" he wrote, recalling the reaction to Walker's attempt to cut back public employees' unions collective bargaining rights. "Thanks to Governor Walker's reforms, it's sunnier than ever."

A limited picture of how much AFP is spending in the state comes from its TV buys. The Federal Communications Commission requires that local TV stations keep information about political ad spending in a public file. As of a month ago, when Gannett's Wisconsin newspapers compiled data from the files, AFP had spent more than $1.5 million on ads in the state's five biggest markets. Sunlight is part of a coalition of media and open government groups that is trying to update the Wisconsin political ad database and, eventually, expand it for the fall election. 

The situation in Wisconsin is likely to be a sneak preview of coming attractions as non-profits on both sides of the ideological divide begin pouring money into battleground states. "Together, we've helped restore prosperity to the Badger State," the AFP email closed. "Now, onto the rest of America." In case that was too subtle, the embedded video ended with three words on the screen: November Is Coming."