Grain Operator Austin Clubb surveys corn inside the Homestead Grain Facility at Amana Farms near Cedar Rapids, Iowa. John Poole/NPR hide caption

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A composite image shows part of the NPR/Center for Responsive Politics reporting team's whiteboard at NPR headquarters that was used to map out how Wellspring connects to other social welfare groups. (Click the enlarge button to see a full-size image.) John W. Poole/NPR hide caption

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The Au Sable River in Michigan is a popular place for fly fishermen and the heart of a debate unexpectedly influenced by largely invisible social welfare organizations. Christine Arrasmith/NPR hide caption

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Vice President Joe Biden swears in Sen. Cory Booker (D-NJ) as his mother, Carolyn, holds a Bible on Thursday. Chip Somodevilla/Getty Images hide caption

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An evening view of the Exxon Mobil oil refinery complex in Baton Rouge, La. John W. Poole/NPR hide caption

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The Houston Ship Channel is home to a wide range of heavy industry, including chemical processing plants and petrochemical refineries. Richard Harris/NPR hide caption

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