I don't think state or federal government, business (large and small) or many others want the flow of Mexicans or OTM's to stop. To the governments - it's just more tax base via working age persons. To the businesses - it's just more cheap labor that includes the side benefit of persons that are in a weak position to complain or file suits about pay and safety etc.
Like I said - the people in a position to make law changes or to enforce existing laws likely have a vested interest in the status quo. If you can't beat them - then join them? Deep down - I feel that our national leaders are intentionally allowing the illegals to come here to pad a slowing birth rate to shore up our supply of working age persons because we are going to need them when the baby boomers are gereatric and into the future. Europe has done so with all sorts of Mideastern, North African etc. I - personally would take a Mexican any day rather than what Europe is getting.
Yes, I've often said I'd rather have Latin Americans coming in than Muslims. We are very lucky in that regard.
But if you look at the history of the past two centuries in Latin America, you find something very disturbing: None of these countries are capable of governing themselves without constantly falling into left or right-wing dictatorships. I'm not at all sure whether we can change that pattern if, in the future, the majority of our country is Latin American.
I don't know what it is. Most of them are nice people, individually. But they have rarely managed to live together under a just political system.