In the short term they are destabilizing our society. In the medium term they are erasing it by displacing the population. As for right now, they are throwing us out of work. A few graphics from Zero Hedge using US Bureau of Labor Statistics data tell the story (multiply the numbers by 1,000):
As Zero Hedge notes, the data show that
in August a whopping 698,000 native-born Americans lost their job. This drop was offset by 204,000 foreign-born Americans, who got a job in the month of August. …since December 2007, according to the Household Survey, only 790,000 native born American jobs have been added. Contrast that with the 2.1 million foreign-born Americans who have found a job over the same time period.