Well, one of the few instances of immigration I'm not totally against is that which occurs when there is a natural disaster. The Central American immigrants in the above story claim to have entered this country due to hardship conditions, caused by natural disasters.
However, it's been a long while. Every day they continue to stay, they become more entrenched, and more difficult to get them to return.
Wouldn't it be easier (and cheaper) to give each one of them $1000-$2000 and tell them "It's time - adios!"