They don't come in and take jobs away from regular 'Mericans. That is a myth.
They do the jobs that without them would go undone. And the way to stop them from being criminally underpaid is to decriminalize them, and give them rights.
Like every other immigration opponent, your real problem with the influx of new people is not economic. It is cultural. They pose a threat to what you think the United States should be.