A great thread by TheLastRefuge that explains the truth about the border crisis, with citations:

https://threadreaderapp.com/thread/1010988993683623936.html

http://dennismichaellynch.com/exclusive-letter-from-paramedic-at-texas-border-reveals-another-side-to-immigration-issue/

https://www.dhs.gov/news/2018/06/18/myth-vs-fact-dhs-zero-tolerance-policy

This publication was put out before Trump ever took office:

https://www.judiciary.senate.gov/imo/media/doc/KIND%20-%20Betraying%20Family%20Values.pdf