A few articles that argue for border security, tighter immigration laws and related from a Catholic perspective:
Chilton Williamson Jr., A Christmas Meditation: St. Augustine on the National Question.
Idem, Rediscovered: The Nation-State In The Western Tradition.
John Zmirak, Christmas Meditation 2002: Christ, The "Other", And Counterfeit Citizens.
Idem, The Brogue Wears Off: Why The Catholic Church Is Addicted To Immigration.
Idem, Christmas Meditation 2003: This Royal Night.
Idem, The Virgin on the Border: A Christmas Meditation.