The issue of federal preemption in the field of immigration has been swirling more and more strongly in academia, the courts, and even the public consciousness' ever since De Canas v. Bica was decided in 1976.
Weber, David P.
"State And Local Regulation Of Immigration: The Need For A Bilateral (Reciprocal) Ratchet,"
ILSA Journal of International & Comparative Law: Vol. 18
, Article 4.
Available at: http://nsuworks.nova.edu/ilsajournal/vol18/iss3/4