For all amongst us who have escaped from such neighborhoods and areas, and our like minded fellow citizens who are foreign born legal immigrants, who escaped from even worse situations...WE all “go there” because tolerating such things is not an option in our society.
The “large groups of people” unable or unwilling to abide by our social norms are more than welcome to leave.
“Because the USA is not Europe, and few among we citizens want apartheid or balkanization.”
What we might want and what we get are often two different things. While we might want the underclass in fergidishu, detroit, chiraq and other places to observe prevailing social norms, its obvious that will never happen. And they’re not leaving, either.