The whole thing is a very complex economic problem. First off, I don't know why you're crying about farmers since they make, on average, about $50,000 more than the average US household. That average includes all the 40 % of farms that are "gentleman ranches" that are nothing more than tax evasion and drag that average way down. On the other hand, there is the economic issue of raising wages which will push one of America's greatest export industries out of the country. We've already seen this with the Coalition of Immokalee Workers in Florida gaining wage increases that pushed tomato production to Mexico. Then you have to get political and start talking about trade tariffs (which with a massive pay increase Mexico should agree to instantly as the remittances would be huge) and then get more political about the problem of one state enacting a rule that makes their growers and ranchers noncompetitive with other states. After that, you have to get into the border security issue that some farmers make a competitive advantage of by hiring undocumented immigrants (yeah Trump haters, law abiding farmers and ranchers have a valid complaint here about border security). Any bill would also have to include product specific regulations.
People may scoff, but that's a pretty damn good compensation package for someone from a poor country. You are literally raising people out of poverty, so big ups for that.
Average Mexican household income is something like $12,000. That's average. Some of the poorest areas make no more than $5.00 per day. They also work over 500 more hours per year than the average American. You are providing a seasonal job for a father who can make more in six months than many Mexicans make in 2.5 years. Add in the food savings and a willing man can send home just half of his annual salary to live a typical Mexican lifestyle.