Vox:
Trump wants to protect American jobs. His immigration bill would make us poorer.
3 August 2017
Basically the only American-born group that you could even plausibly argue are harmed is high school dropouts. This is a fairly tiny group, but it’s not even clear they are harmed. Research by the University of Bologna's Gianmarco Ottaviano and UC Davis's Giovanni Peri finds that immigrants help the wages of even low-skilled American workers.
Related publications
‘Rethinking The Effect Of Immigration On Wages’. Gianmarco I. P. Ottaviano, Giovanni Peri, 2011. http://onlinelibrary.wiley.com/doi/10.1111/j.1542-4774.2011.01052.x/full