“The flood across the border will turn into a tsunami as they starve in Central and South America.”
Or ... the migration may start going the other way. There are lots of low-maintenance fruit trees in Central America. They still use a lot of oxen teams for plowing. They use lots of natural fertilizers. The large corn fields and cane fields get plenty of petro-based fertilizers but the first year without those will lower the yield but the harvest would still be substantial. They already ignore the protections on such things as sea turtle eggs and more harvesting prohibitions and/or limits would be ignored if things got tough.
Or ... the migration may start going the other way. There are lots of low-maintenance fruit trees in Central America.
Only an idiot would move from his upscale neighborhood over to murderous, across-the-tracks Shanty Town merely because of the fruit trees.
Regards,