These difficult jobs are held by illegals because employers are able to price the work below market rates because of the existence of illegals. But for illegals, the jobs would pay more. In effect the employers are using illegals to work as if they were almost slave laborers. By advocating against restricting illegal immigration and in favor of illegals continuing to hold these back-breaking jobs at inhuman pay, the Catholic Church is protecting slavery.
If farmers and businesses are unable to find local workers and have to hire illegal immigrants that tells me the problem is with the guest worker program which should be allowing the enough of the needed workers in on a temporary basis. So maybe instead of claiming we need to open up the borders willy nilly we should find out why enough legal workers are not being allowed into the country.