Legal immigrants have been coming to the U.S. during harvest time for half century+, I know, I use to pick crops with them as a kid. (I have mentioned this before) They than go back after the harvest season. Please let me know when lettuce is going to $12 in my area, I'll have a trailers of them for you if you wish.
We actually have a shortage of skilled labor... not unskilled labor, but most of that is cause by the millennial generation i.e. we're paying people not to work. That is were the real $12 lettuce come from. Illegals are not going to pay for their share of services by picking lettuce bro.
All of the illegals are completely unskilled, uneducated, and of no real use... as a generation. Either way, you don't have a country without a border.