It doesn't matter who was nominated the same thing would have happened.
Look at the cases coming before the SCOTUS in their first session for the answer to why they are so scared.
Nielsen v. Preap
Docket No. Op. Below Argument Opinion Vote Author Term
16-1363 9th Cir. Oct 10, 2018
TBD TBD TBD OT 2018
Issue: Whether a criminal alien becomes exempt from mandatory detention under 8 U.S.C. § 1226(c) if, after the alien is released from criminal custody, the Department of Homeland Security does not take him into immigration custody immediately.
http://www.scotusblog.com/case-files/cases/nielsen-v-preap/