If you wonder why he brought the subject up, perhaps you should ask him.
As are you. Your presumptions are on one side of the interpretations and mine the other side. What you're saying is your interpretations are correct and mine are not. Why is that since we are both left to divine what he meant with such a nondescript word as immigrant. There are two meanings to that word, illegal and legal. He stayed in the middle of that argument by just saying immigrant, not committing to either one.
Just go over FR's articles on illegal immigrants. That's the hot button issue in our country today, not legal immigrants.