Leo Perrero still remembers the humiliation of losing his job. “All of you in this room will be losing your jobs in the next 90 days,” he was told, later recalling the experience before Congress. “Later that same day,” he added, “I remember very clearly going to the local church pumpkin sale and having to tell the kids that we could not buy any because my job was going over to a foreign worker.” Disney replaced Perrero using a little-known and oft overlooked provision of immigration law that allows big tech companies to replace their employees with foreign workers under...