People have always moved from one place in the world to another. f they were relatively powerful those who moved oppressed the aboriginal people, as happened in Australia, the Americas and in most other places in the world.
It seems impossible for large numbers of people to move from one place in the world to another without oppressing, to some extent, those they meet and whose land they wish to acquire.
Vast tidal waves of people moving across the world brings changes and folk tend to dislike change, except as a concept. The politician who promises change is really making a promise that there will be no change, just minor improvements. Those who lead people into the land of others (be it Moses or Cortes) promise not merely change but by the standards of the inhabitants of the land they invade, revolution, the destruction of a culture and often death, either deliberately or accidentally by introducing new diseases.
Today in the developed world we think of immigration as a problem, not because our culture or lives are threatened, but for other reasons built into our DNA over thousands and thousands of years. We see folk trying to seek a better life being drowned in the seas or burned in deserts or shot in their attempts.
The promise of a better economic life is usually a promise with the same features of a politician’s promise, and frequently comes to naught.
What we should remember when we see the attempts of those seeking to immigrate, is that our forebears were once strangers in a new land, who displaces those who had lived there.