Today, as I said to my discussion group, "I'm going to talk about immigration for a minute. If I think I am getting nowhere, I will undoubtedly just cancel this. If you see it, that means I intend to use all or part of what I have written here in a public piece of social commentary."
Another factor uniting SOME of these peoples' immigration is that they weren't brought here by choice, or under good faith.
Notwithstanding that, it is fair to say that the majority of immigrants to the United States, up until a certain point in time that (in my opinion) coincides with the End Game of the Cold War and the beginning of computer ubiquity, yearned for admission to the United States because it appeared to be a land of limitless opportunity for a man or woman willing to work hard, the old New England ethic.
They had naive but understandable dreams about the land of freedom and unlimited space and resources to grow themselves. In a day before mechanization and expenditure of fossil-fuel resources-- machines were being invented and applied, particularly in England, but the industrial age hadn't really taken hold till well after the Civil War-- this was particularly understandable.
Probably some number of truly uninformed people-- i.e., people who remain outside the boundaries of computerization-- still entertain such dreams. But at this point, among literate people of any language, the information about the United States that they receive must give some of them reason to CALCULATE their reasons for attempting to emigrate one way er nuther, rather than just making the move on blessed blind faith.
America is no longer the land of the free, the home of the brave (and it never has been JUST that-- it's a helluva poem, and that's just the first verse), it is the empire. We have military outposts or ongoing actions in 129 nations.
So we're purty much down to people who calculate that their chances of not getting killed are better in the US. Many of them are from other continents. The killing is up close and personal in almost all Asian and African theatres and occasionally spills over into Europe.