Apparently, some folks don't know the back story on Mexico. Here it is: When Clinton pushed through the North American Free Trade Agreement (NAFTA) in 1993, U.S. corporations were put in a position to gut the Mexican economy, which they have done. Those corporations (and even individual rich Americans) have bought up land in Mexico, displacing Mexicans who have been living on that land and growing the food for their families on it for thousands of years.
This forced poorer Mexicans to work for the corporations for pennies a day while we buy the products made by them for the same price we would be paying if they were made by U.S. workers (tens of thousands of which lost their jobs when NAFTA was signed -- see below). The corporations make out like bandits (literally) and the Mexicans starve.
The rampant poverty NAFTA produced in Mexico is what gave birth to the drug cartels (which were originally formed with the assistance of the CIA, by the way, as outlined in the movie "American Made"). And this is why Mexicans (and other Central Americans) come here like they do. Some leave their families behind. Some can't bear to do that. Besides it's dangerous. And so-called "legal" migration takes decades and costs a lot of money.
The real reason Trump is locking up immigrants is because millions of dollars (our money) is going into the pockets of those who created private prisons expressly for this purpose while U.S. farmers are going belly up because their crops are rotting on the ground and we're going to pay $5 a pound for imported food immigrants used to pick right here in our country.
Then, while we're all utterly focused on babies in cages, the present Administration is using Congress to push through legislation that will leave us without health care, without higher education, without workplace and environmental regulations necessary to the common good, and without protection from a run-amok criminal injustice system. Now you know.