When the southern border was more porous Mexican workers would come seasonally, work the agricultural jobs most Americans still don’t want to work and go home with a bundle of green backs for their family. After Vietnam one of the generals who was feeling like shit for having had his ass handed to him, applied for the job of border management and amped everything up. This forced many Mexicans to choose to stay when they successfully crossed the border rather than gambling on not being able to get back. Sometimes the outcome you hope for doesn’t quite work out.