Jobs are made possible by consumption. Illegal immigrants are consumers too.

Without them, we'd have fewer workers competing for jobs, which seems like a good thing, but we'd also have fewer jobs to go around because of decreased consumption.

That's a fine theory but do you have any proof?

This episode of the "Science Vs" podcast goes over a lot of research on immigration including what I mentioned about job creation: https://gimletmedia.com/episode/immigration/