I used to very much believe that the Schengen Agreement was the greatest thing since sliced bread (and was, additionally, very pro-Euro in that respect), but would posit what transpired as its member states too rapidly expanded as a marquee example of why open-borders are, more often than not, a risky proposition. In Europe, problematic symptoms presented almost immediately; brain drain out of the East into the West, Roma population congressing in wealthy metropoles like Paris, cross-jurisdictional red tape galore. Of course, Western Europe initially thrived off of the influx of cheap (and talented) labor and the East was content with a new streams of revenue, primarily related to real estate. The hope was that this kind of mutual back-scratching would evolve, over time, into a better, more 'level' Europe.
The problem is that the playing field never equalized. At the end of the day, it's still vastly more preferable to live in France than in Slovakia in general terms of quality of life. Plus, on top of that component of the Schengen philosophy faltering, sprinkle in the global financial crisis and its subsequent finger-pointing and austerity measures/protestations, as well as Syrian refugee crisis, for good measure. It's a mess - but the population displacement has already occurred, for better or worse. And now, taking Greece as a prime example, an open-border mentality has created a situation where one country has suffered from so much emigration that it's fallen into a hole that will take generations to crawl out of.
Is the 'arrangement' we've had, to date, with Mexico really so different?
With respect to open-borders in North America, it wouldn't take much to persuade me to open the border between the United States and Canada. The standard of living between the two countries is highly comparable and you aren't likely to see much of an exodus in either direction. Mexico is a different story. To your point, we've talked about "making Mexico better" for years, but the situation doesn't seem to have improved, even an iota, over the past decade. Meanwhile, it's clear that our system has been strained (and, sure, I do believe that rhetoric like "taxed" ... "on the brink" ... "overran" is perhaps a bit much) by the influx of illegals from the South. And of course there's the drugs.
So, to come full circle, I'd still likely use the same phraseology toward an individual who subscribes to an open-borders belief system as it pertains to Mexico and the United States. Delusional not from being willfully ignorant of the repercussions of unbridled Mexican immigration into the US, but delusional in thinking that an open-borders philosophy is any sort of real solution here for either of the two countries. Maybe I'm too grounded in the political/economic realities. I can certainly appreciate the anthropological, globalist approach that is rooted in an open-borders mindset ... but this is a different case.
Hell, I'd even be somewhat comfortable making the argument that putting up a wall (or, for the sake of debate, making the border airtight) is actually likely to be more beneficial for Mexico and Central/South America than for America in the long-haul. It is a solution that could actually make open-borders a reality more expeditiously than whatever it is that's happening now.
