I was travelling in the US and saw a lot of foreign people from countries like Mexico, Israel, China and India who don't have any specific academic degree and don't speak English properly. They have ordinary jobs, nothing that another American citizen couldn't do. Why were they allowed to move to and live in the US, while the path to immigration can seem so difficult or strict for other, more academically qualified, foreigners, for example those from Europe?
EDIT: I traveled back to USA and again noticed even more the same phenomenon... tons of people that barely speak English from same countries mentioned above plus Africa. And they were not tourists.