President-elect Donald J. Trump is to be inaugurated Monday and his mass deportation program is slated to begin Tuesday. While a number of Catholic bishops have spoken out against Trump’s deportation plans (I’ve covered the subject for The American Spectator here, here, and here), the Catholic Church has actually long supported the right of nations to defend their sovereignty, their borders, and their national culture and identity.

The Catholic Church’s teachings on national sovereignty, culture, and identity are perennial and immutable.
The Church and the Sovereignty of Nations
In what would surely be characterized as a nationalist hate screed if published today, Pope Leo XII wrote in 1885, “Nations have their own distinct character and genius, bestowed upon them by divine Providence, and it is the duty of the state to ensure that these unique identities are respected and fostered in the development of society.”
In 1937, Pope Pius XI wrote that the Catholic Church “never places limits to the rights of individuals or nations to develop according to their ethnic characteristics.” The Pontiff’s encyclical Mit Brennender Sorge, written in German instead of the usual Latin, was intended as a warning against the ascendant Nazi regime which was about to ignite the Second World War. Thus, Pope Pius XI cautioned, “However, it [the Church] strongly condemns any exclusion or superiority that leads to division and discord.”
It is worth noting that even in the midst of Germany’s descent into the violent ideology of neopagan Nazism, the Pontiff upheld the nation’s right to value and preserve its ethnic heritage.
Two years later, Pope Pius XII continued his predecessor’s work, strongly condemning racially-motivated violence and ethnic cleansing while firmly supporting a nation’s right to protect its ethnic and cultural heritage. In Summi Pontificatus, he wrote, “In the unity of the human family, races, and peoples have their own characteristics which they may and must guard, pres...