When people get here, they get jobs, and support themselves, it is not rocket science. If where you live sucks, and you move, you get a job and start your new life.
People who already have been here and have family can move in with a parent/grandparent/relative/friend etc if they lose their job, get a divorce, have their house burn down, whatever right? How is it any different for anyone else moving a little further. It is not.
The mindset that these people are coming here with nothing and won't be able to support themselves is easily countered by a few hundred years of actual historical evidence of immigrants helping our country economically.