Maybe your immigrants are taking pride and ownership of their adopted country and not just there for the freebies.
Where I live, illegal immigrants come to the county hospital (Parkland Memorial in Dallas) to have their babies. They don't speak English, won't pay for service and the county has to pick up the tab. Now they have an "anchor" to give them the "right" to stay here and suck up as many benefits as govt. will hand out. Their pride and allegiance is not here, they don't need to learn the language, they proudly fly their nation's flag and we are dumb enough to pay them to stay.