For years and years there was an informal guest worker program. Farmers and fruit growers had a need for farm labor -- work that was not much favored by Americans. Contrariwise, Mexicans needed the work. The informal arrangement with guest workers was formalized, during wartime in 1942, under the Bracero Program. which at its height allowed over 400,000 workers. At its height it allowed over 400,000 workers matching demand with labor and legitimating the migrants for their seasonal stay. When the season ended, they would return to their families. Of course, as in situations where all power is centered with employers, there were abuses -- and much continues to this day with undocumented workers.
In the 1960 presidential election, John F. Kennedy seized on the issue to earn votes. He said the farmers by paying less and using foreign labor were undermining U.S. workers. The problem -- for that is what it had now been made into -- gained such traction that Kennedy's successor, Lyndon Johnson, ended the program in 1964.
But a law does not diminish the need for labor, so the business went underground. The law had not criminalized the hiring of illegal migrants, so Mexicans continued to come, although without documents. At the end of the season, they could still go back to their families because it was easy to cross the border.
As might have been expected, next came pressure to tighten border controls which they did, hiring more border patrol agents, putting up fences at the easiest crossing points and increasing vigilance. It was no longer easy to go back to Mexico after the season to stay with family, for the return trip to the U.S. had become hazardous. The temporary workers became a permanent fixture. They naturally sent for their families, and communities of illegal migrants sprang up. As is clear, they did not want to come to the U.S. -- that was not their first choice; they were forced to because of repeated short-sighted government efforts.
Then came NAFTA which halved the price of corn in Mexico (due to cheap subsidized American imports) and forced Mexican farmers off their land. Where could they go but north and families followed. Add U.S. initiated regime changes in Central America -- persecution of labor leaders, extra judicial killings and general chaos there -- and waves of people fleeing chaos added to the undocumented immigrant population. That number is now a little over eleven million, approximately three percent of the total U.S. population. If Libya, Syria and Iraq had been on this continent, one could easily have added another million (or two) to the figure.
President Trump, nobody wants to leave their home; they are usually obliged to -- like your grandfather deported from Bavaria, where he wished to live, for illegally dodging his required military service. (Only psychotherapists can assess the subconscious influence of this family trauma and your fascination with military generals.) Immigrants are here because of the unintended consequences of American laws and policies. One caveat then is, be careful what you wish for. That wall we hear so much about ... we can only hope you and your team have thought through all the implications and eventualities. Who knows there might be a reverse exodus of those sickened by the ersatz Louis Quinze kitsch and a Trumpian dystopia.
In 2014 aboard Air Force One, President Barack Obama summarized his foreign policy in the pithy phrase, 'Don't do stupid shit'. In the first sixty days of the Trump presidency, it appears to most observers that his successor somehow failed to hear the 'don't'.