by Michael Keller

Unlike super PACs, 501(c) groups can accept anonymous donations. Also unlike super PACs, they have to disclose only how they spend some of their money in real time. (The rest gets disclosed in annual reports to the IRS.) As a result, there’s a lot we don’t know about how much money is flowing into or out of these groups during this election cycle—though we can be sure that it’s a lot.

One of the few other things we can say with certainty about 501(c)s is that, to a surprising extent, they often work together. In an attempt to map out what this world looks like, we partnered with the Center for Responsive Politics (CRP), which sifted through tax filings from 2010 and 2011 in order to create a picture of the financial ties between many of these organizations. (Numbers from this year won’t be available until mid-2013 at the earliest.) This map shows donations from one organization to another, with arrows depicting which direction the money went. READ FULL ARTICLE: The Dark Money Shuffle: The strange, opaque world of politically minded nonprofits.

For an explanation of CRP’s methodology in compiling these numbers, click here.