No president has ever put pressure on Mexico this way.    The Mexicans always said that an open border was a relief valve. If we clamped down on illegal immigration, all those migrants would go home--poor and pissed off--and they'd overthrow the Mexican government.    Then Mexico would become a failed state like Somalia, and we'd have to invade, occupy, and nation build. There are multiple studies outlining this scenario.    http://theweek.com/articles/509393/mexicos-failed-state-threat    https://ccis.ucsd.edu/_files/wp54.pdf    Trump said, "You're using the threat of becoming a failed state to blackmail us. Well, we'll just wall you off and let YOU deal with the hell you created by being corrupt and dishonest."   As we keep seeing, everything we were told before the Trump Era was a lie.    Although that's extremely horrifying to contemplate, at least we lived long enough to see it all change.    God bless Donald Trump.