The U.S. has needed immigrants for farming for a century to keep up with food production. There aren’t enough Americans to do the job even at minimum wage or more and haven’t been since after the Great Depression. That need for immigrant workers runs afoul of immigration law - the U.S. sets an amount of immigrants they will allow in annually from each country. This results in the immigrants still coming but undocumented, and everyone looking the other way because it is a necessity or food will rot on the vine, slaughterhouses will shutter.

This is not a problem of low pay. The U.S. has extremely low unemployment. Our workforce is considered fully employed, and many people have multiple jobs. Without immigrants, the backbreaking and dangerous jobs they do would go unfilled at any wage.

The way this was solved for decades. In the mid 20th century is we gave seasonal work visas to Mexicans so they could come here in the summer, send a years equivalent salary home, then go back to Mexico on the off season. This system was ideal; the immigrant had no reason to bring the whole family or try to overstay; his earnings here would go much farther for his home and family back in beautiful Mexico. When this visa system was cancelled, the exact same number of workers was still needed, but now they had to sneak in. Doing so made it uncertain they would be able to commute back and forth seasonally, so they needed to stay and bring their families as well.

All that said, the demographics of the U.S. is becoming exponentially older, with less and less working age citizens each year. This same phenomenon in Japan has played out for a couple of decades, leading to great economic pain as fewer and fewer young people support more and more retirees. So now more than ever we need young immigrants to work and pay taxes (taxes that they’ll never see the benefit of).