We built a house a few years ago. Our best crews were mostly Spanish speaking. They showed up on time, were polite, had great attitudes, and worked hard. One crew of 5 had one car between them, lived in a two bedroom apartment, and sent most of their money to their families. Contrast that to other home grown contractors who showed up late, had an attitude (you want the light switch inside the bedroom?), and generally were a pain to work with. I don't know the immigration status of the first crew, and I don't agree with people coming illegally, but I'd hire the first crew again any day.