Because they have no choice. It's so hard to cross the border, that once you're in, you have no choice but to stay in. They also bring their families in, becaus

Because they have no choice. It's so hard to cross the border, that once you're in, you have no choice but to stay in. They also bring their families in, because otherwise they would not see them. Implement a farmworker visa that lets these workers go back and forth as needed, and suddenly they don't have to bring their families here; they can go back for events and festivals, maintaining a healthy social life. They can't be blackmailed by criminals, because they're here legally. You can even charge them a little bit for catastrophic health insurance.