I had the privilege to live in various parts of the world. When I was young, I lived in Italy - the part I experienced as an immigrant was definitely a shithole. I recall watching kids climb all over a large garbage dump looking for things, as my train emerged from a tunnel under the Alps and entered Italy. I remember packs of wild dogs roaming the streets of a small town where we waited for our entry visas to the U.S. At one point I got into a fight with some local kids who viewed me as a traitor to communism. If Italy was not such a shithole then, there would not have been so many immigrants from Italy coming to America. The Soviet Union republic I left, was also a shithole. Modern apartment buildings had proper toilets but just outside of my building, there was an outhouse with a - you know what. I bet it is still there. Many of the older private homes had no plumbing and some had to carry water into their homes from a street hydrant.
Living in New York, I can say with confidence that much of Queens county, as well as Kings (Brooklyn), are shitholes. Things were worse before Giuliani, but they still retain their shithole status. Most of Manhattan is nice - if you can afford to live there. South Bronx is and will likely forever remain a shithole. Parts of rural US are also shitholes. People there are rightly depressed, on drugs, and unemployable.
I have no problem with people from shitholes outside of U.S., moving to shitholes within the U.S. My only request is that they pay for their own shitholes. In other words, they should not be moving here to make use of our shitholes without paying their way and for the use of facilities. Nor do I want to spend my own money to build proper facilities for them overseas. If they try to dirty up a proper civilized lavatory, they should be punished enough to deter others from doing the same.
In an ideal world, we would only select those who can come here and build proper sanitary facilities in our underdeveloped regions. We used to do that in past: you had to show that you brought the type of skills this country required and would not become a financial burden on the people here.
To me, that is a proper policy of immigration.