The Service Employees International Union, besides representing 2 million workers, is one of the most active and powerful political organizations in the nation. Beyond its own direct efforts, which are vast, the union also helps create, lead, and fund dozens of other organizations and coalitions that are influential in public policy debates and elections. NPR and CIR investigate.

>> Listen to the story on NPR.org.

>> View a chart of SEIU’s financial and political connections.

Will Evans is a senior reporter and producer for Reveal, covering labor and tech. His reporting has prompted government investigations, legislation, reforms and prosecutions. A series on working conditions at Amazon warehouses was a finalist for a Pulitzer Prize and won a Gerald Loeb Award. His work has also won multiple Investigative Reporters and Editors Awards, including for a series on safety problems at Tesla. Other investigations have exposed secret spying at Uber, illegal discrimination in the temp industry and rampant fraud in California's drug rehab system for the poor. Prior to joining The Center for Investigative Reporting in 2005, Evans was a reporter at The Sacramento Bee. He is based in Reveal's Emeryville, California, office.