The U.S. Postal Service faces an $8.5 million budget shortfall this year. NPR is broadcasting a series of stories about cuts in postal services and facilities and the lives and communities already being affected. One person with great insight into the social history of the USPS is Philip Rubio, author of There's Always Work at the Post Office: African American Postal Workers and the Fight for Jobs, Justice, and Equality, which looks at the critical role of black postal workers in the U.S. labor and black freedom movements. Rubio joined in a discussion last Wednesday...