Pat Tourney, who lives in Detroit, said she hasn't worked for the postal service but turned out Thursday to join the protest. Holding a sign that read "SAVE THE USPS," she said that, as a customer, she believes in the post office.

A sale of the U.S. Postal Service would raise rates, shutter post offices and threaten service in rural Minnesota, unions say.

Nearly 100 postal workers and union supporters rallied at the Des Moines Post Office against a feared move to privatize the U.S. Postal Service