Inside the ground-level Staten Island apartment that serves as the operational headquarters of the Amazon Labor Union, Chris Smalls is spitballing about real estate. Wearing immaculate Air Jordans and boxy sunglasses, surrounded by half-empty pasta boxes and a pot of old mac and cheese, the leader of the first successful union drive in Amazon history is talking with Julian Mitchell-Israel, the ALU’s field director. Maybe, Mitchell-Israel muses, the union’s next headquarters could be in a bodega.

Nah, Smalls says, with the smallest shake of his head. “We’re a big union. Not a bodega union.”

By conventional standards, the Amazon Labor Union—just a year old and less than 10,000 members strong—isn’t actually that big. Not when com…