The Roman Empire made the grave error of granting citizenship to those who were not acting in the interest of Rome.
Sound familiar? History repeats itself, and often with disasterous consequences when ignored.
Rome made other grave errors, like encouraging the super rich. Many of whom were absentee landlords whose land was managed by slaves and serfs who had no incentive to maintain fertlity. Our super rich send work overseas to cheap labor so they can keep their hyper inflated salaries and perks and pay stockholders enough to keep them happy. Then they wonder why we have so many poor, unemployed, and dangerous or run down areas where they wouldn’t want to live and complain that America is going to the dogs.