For a bit of context, consider the fact that 10 months before the election, AFP already has spent $6 million in North Carolina alone in an attempt to knock off Democratic Sen. Kay Hagen. That is more than three times the money that likely Democratic candidate Mary Burke has reported raising in the first months of her campaign. It also represents roughly 80 percent of the total that the Greater Wisconsin Committee, the state's most significant pro-Democratic outside spending group, spent in all of 2012, a year that featured a presidential election and a the gubernatorial recall election.

This suggests that Americans for Prosperity, which boasted spending $10 million in Wisconsin in support of Walker in 2011 and 2012, can be expected to once again be a major force — if not the major force — in this year's gubernatorial election.

As I described in a recent article about "dark money" political organizations, it is difficult to track the extent of AFP's involvement in state politics, particularly as it is happening. That is because AFP, which is registered as a tax-deductible charity, does not run ads that expressly advocate for the election or defeat of candidates.