The folks at the MacIver Institute for Public Policy, a Wisconsin-based free market think tank, have compiled a stunning infographic on the network of liberal groups, most of them labor unions, that have poured money into the State Senate recall elections.

The elections, which will be held Tuesday, are the latest battle in an ongoing political war in Wisconsin that began with Gov. Scott Walker’s budget reform bill, which trimmed the ability of the state’s public sector workers to collectively bargain.

The MacIver Institute’s data was all gathered from official records filed with the goverment of Wisconsin. Click the image above for a larger view.

MacIver explains:

These figures include direct contributions from political action committee to candidates, coordinated independent expenditure campaigns, and individual third party expenditures. The overall effort, however, is likely much larger. Member-to-member communications and issue advocacy totals are not required to be reported to the Wisconsin Government Accountability Board and are therefore not included in this total.

For more on the recall elections, check out Scribe’s interview with Wisconsin Governor Scott Walker.