I don't think you understand.   You can read it right here in this article -- the bishops have time and again declared their support for illegal immigration.

You'd have a point if the bishops were against illegal immigration.   But they are actually not even Swiss about it, they are most definitely pro illegal immigration, and pro amnesty for all illegal citizens.

The bishops in Mexico have said that our laws that enforce our border are an act of "terrorism."   Were they rebuked by Rome for that?  Nope, because the pope is on their side.