On Monday, we took you inside one of the biggest political operations in the country – a sprawling network of politically active nonprofit groups backed by the billionaire industrialists Charles and David Koch and other conservative donors. Working with Robert Maguire, a researcher at the Center for Responsive Politics who tracks nonprofits, we calculated that a coalition of 17 groups raised at least $407 million in the 2012 election cycle. Much of that was spent on get-out-the-vote efforts and ads attacking President Obama and congressional Democrats.

Tracing the flow of money required pouring through hundreds of pages of tax returns and mapping out the connections between the groups. Much of the money was transferred to LLC subsidiaries, known as disregarded entities, that are wholly owned by the recipient groups. The network also gave millions of dollars to other outside groups allied with the GOP.

For more details on how the funds moved through the network, check out The Post's visualization below. Click the image to view a larger version.

Below is the source graphic, by Robert Maguire of the Center for Responsive Politics. Click to view a larger version.