"Although states may exercise their police power in a manner that has
an incidental or indirect effect on aliens [immigrants], a state may not
establish its own immigration policy or enforce state laws in a manner
that interferes with the federal immigration laws. The Constitution and the
federal immigration laws do not permit the development of a patchwork
of state and local immigration policies throughout the country."
-U.S. Department of Justice, July 6, 2010
Which part of the federal system is illustrated by this excerpt?
A
inherent powers
due process of law
C
the supremacy clause
D
equal protection of the laws