14th Amendment

Amendment XIV

Section 1.

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

http://topics.law.cornell.edu/constitution/amendmentxiv

The STATE is allowed to enforce US LAW, (US CODE Title 8) (Read the whole section)

http://www.law.cornell.edu/uscode/8/usc_sup_01_8_10_12_20_II_30_VIII.html

The Arizonal law does nothing more than enforce existing US LAW. It is constitutional, unless you want to say US CODE TITLE 8 is unconstitutional?