I didn't downmod you, but a couple potential issues are:

- The job market isn't always a zero-sum game, so immigrants aren't always "stealing" jobs from citizens.

- Illegal immigrants are often in low-paying jobs involving manual labor, jobs that many citizens wouldn't consider even if they were available. (Anecdotally, I know one landscaping company that offers all their jobs to legal immigrants/citizens first, and if no one takes them they go to H-1B visas, and if those run out they start looking at illegal immigrants.)