Immigrants should learn the native language.

So Anglos should learn Spanish if they live south of the old border with Mexico.

Source: The Economist

So did the people of Mexican origin come to the United States, or did the United States come to them? Clearly some of them came here and we expanded to include some of them.

Incidentally, the Four Corners area (where New Mexico, Arizona, Utah and Colorado meet) has large populations of American Indians, who were also there when the United States arrived.