A long time ago, in a land far away, not too far from the Ten Commandments–only two chapters removed in the Pentateuch–a prescription for welcoming immigrants:
103. A similar approach is found in the Old Testament: “You shall not wrong a stranger or oppress him, for you yourselves were strangers in the land of Egypt” (Exodus 22:21). “When a stranger resides with you in your land, you shall not oppress him. The stranger who resides with you shall be to you as the citizen among you; and you shall love him as yourself; for you were strangers in the land of Egypt” (Leviticus 19:33-34).
If United States Americans think they can wear the mantles of Judeo-Christian tradition and anti-immigration rhetoric without a large helping of hypocrisy, well …
This is not a notion invented by some Pope, or a momentary fad. In today’s world too, we are called to follow the path of spiritual wisdom proposed by the prophet Isaiah to show what is pleasing to God. “Is it not to share your bread with the hungry and bring the homeless poor into your house; when you see the naked, to cover him, and not to hide yourself from your own kin? Then your light shall break forth like the dawn” (58:7-8).
I would hope this advice that points to holiness is making people uncomfortable. Discomfort can be a sign of impending conversion.
You can check the full document Gaudete et Exsultate on the Vatican website.