Republican National Committee Chairman Reince Priebus, speaking before the California GOP spring convention, said recently he doesn't lament the end of public funding for national political conventions. Ben Margot/AP hide caption

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Americans for Prosperity Foundation Chairman David Koch addresses attendees of the Defending the American Dream Summit in Orlando, Fla., Friday, Aug. 30, 2013. Phelan M. Ebenhack/AP hide caption

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A woman signs a giant banner printed with the preamble to the U.S. Constitution during a demonstration against the Citizens United ruling in Washington in October 2010. Chip Somodevilla/Getty Images hide caption

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Sen. Jeanne Shaheen (D-N.H.) in the U.S. Capitol building May 14, 2013. Groups are creating ads in New Hampshire to attack Shaheen 10 months before the midterm congressional elections. Allison Shelley/Getty Images 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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