“Stunning, just stunning, just stunning,†said Sheilah Garland, shaking her head as she stared out the window of the bus rolling along a dirt road next to towering black piles of petroleum coke on Chicago’s Southeast Side. As an organizer of National Nurses United, a labor union representing about 6,000 nurses in Chicago and 185,000 nationwide, Garland has seen a lot. She represents nurses working in grueling and traumatic situations on a daily basis. And the union has picked fights with powerful politicians, including former California Gov. Arnold Schwarzenegger and Chicago Mayor Rahm Emanuel.