Undocumented labor makes the food we have as cheap as it is (along with government subsidies). If that labor pool evaporated we’d see more widespread issues with food rotting before being picked and food not getting processed.
The GOP has literally already done this with those exact effects in Florida, Alabama & Georgia. The farmers I know collectively lost millions. Other farmers had to sell out to BigAg, which was just a bonus knock on effect for these ghouls. I'd bet dollars to donuts that the lion's share of these double digit Haley / GOP protest voters in Red states are in the Ag sector, or some other industry directly damaged by Trump's misrule.
But that is kinda the point of fascism. As long as they have power they do not care about people.