"...it's hard to argue that a flood of low-educated, low-skilled illegal immigrants does not have an adverse effect on the low-educated, low-skilled US citizens..."
It's not hard to argue. At a minimum, the topic is under debate:
https://immigration.procon.org/view.answers.php?questionID=0...
https://www.forbes.com/sites/artcarden/2015/08/28/how-do-ill...