Oh no, according to the Chamber of Crony Commerce, they're a huge boon to the American economy. They're just Doing The Jobs Americans Won't DoTM
That's one of the big myths I want to see slain. There are no jobs Americans won't do. There are jobs Americans won't do for 3rd World wages, however. I know this scenario intimately, having worked in landscaping as a summer job during high school and college. The landscaping labor force was nearly 100% immigrant, and we went around to pick them up in the mornings like a school bus. They would have sometimes as many as 15 or 20 people living in a 2 BR apartment. In one little rental house, they had taken off the kitchen cupboard doors and nailed up chicken wire, using the cupboards as roosting nests for chickens. It's that kind of sh*t. The Chamber of Commerce types say Americans should compete with that.