I don't know that it's fair to say he's created a disaster. The governments of Mexico and some Central American countries have largely created this disaster (and blame where it's due, some of our past meddling in Latin America has had a hand in creating these residual negative situations as well, the US did have a direct hand in creating poverty in some of those countries)
A "border disaster" is pretty much the organic product of a situation where you have one really rich country, that shares a border with the gateway to the "impoverished world". If the US and Canada swapped territories, Canadians would be left scratching their heads trying to find the best way to handle it - with all of the same infighting pertaining to the "idealistic softies" (unpragmatic, yet well-intentioned) vs. the "hard-nosed nationalists" (more pragmatic, yet sometimes finding themselves in the company of xenophobes)
It's a conundrum that very few countries have to deal with, unfortunately we're one of those few countries.
This isn't an issue that island nations like Australia or NZ have to deal with, nor is it a problem that nations that are neighbors with only other countries that are relatively on the same playing field.
For instance, Australia doesn't have to worry about illegal immigration unless someone is the best swimmer in the world...and Norway doesn't have to worry about Swedish and Finnish people trying to sneak into their country (because in terms of benefits and standard of living, there's not a huge difference)