Did they stop people at the border before letting them in?
It makes a huge difference that they weren't welcomed with open arms. Most of the ones who are there really wanted to be there. It's not hard to weed out the trash if you don't welcome it in and pour free money into their pockets.
What politics from both sides wants to teach us is that things are never complex. If you have your little package and something doesn't fit into that package, You don't know what to make of it so you want to dismiss it or then you will have to do the work of reconsidering your assumptions. - Michael Malice