Because the enforcement of the criminal provisions of Federal Law has not been expressly prohibited by the Constitution, it would be reserved to the states respectively. According to the Tenth Amendment of the U.S. Constitution, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."

This is interpreted to mean that the states have implied powers in addition to the powers explicitly enumerated to them in the Constitution.

With this understanding of the Constitution, proponents argue that the disputed SB 1070 provisions are not immigration law provisions, but criminal law provisions.

For example, the provision making it a state crime for an alien to be in Arizona without carrying the required documents is only an enforcement of the U.S. regulation requiring aliens who have been in the country longer than 30 days to have registration documents on their person.

Generally, the Supreme Court has indicated that there is some role in immigration law for states. The Supreme Court has held that "the States do have some authority to act with respect to illegal aliens, at least where such action mirrors federal objectives and furthers a legitimate state goal."

Proponents argue that not only has the Federal Government permitted state enforcement of Federal law, it has relied on states in enforcing immigration law. In the context of immigration, the INA itself requires states to share information about an individual's criminal history with federal agencies responsible for enforcement of the INA.

Conclusion

It is yet to be seen whether SB 1070 is constitutional. As of now, many states appear to believe that it is Constitutional enough, as they are considering similar legislation.

However, it may be premature for states to even consider this legislation. Even if the SB 1070 passes Constitutional muster on the Federal Preemption issue, it would still face strong Constitutional challenges on the issues of Equal Protection and Unreasonable Search and Seizure.

Arizona SB 1070

U.S.C. 8 § 1101

United States v. Arizona, No. 10-16645, from opening statement of John J. Bouma, legal representative for Defendant in 9th Circuit Supreme Court, (2010). Available at http://www.ca9.uscourts.gov/media/view_subpage.php?pk_vid=

Mary Fan, Post-Racial Proxies: Resurgent State and...

Cardozo L. Rev. 103-104 (2010).
Kevin R. Johnson, a Case Study of Color Blindness: The Racially Disparate Impacts of Arizona's SB 1070 and the Failure of Comprehensive Immigration Reform. UC Davis Legal Studies Research Paper Series, 24 (2010).

Arizona SB 1070, §3.

Arizona SB 1070, §5.

SB 1070; 8 USC § 1373(c)

U.S. Constitution, Article VI, Clause 2

Donald E. Lively and Russell L. Weaver. Contemporary Supreme Court Cases: Chapter 6 Federal Preemption of State Power. 28 (2006).

Gade v. National Solid Wastes Mgmt. ass'n, 505 U.S. 88, 98 (1992)

Lively, Donald E.; Weaver, Russell L. (2006). Contemporary Supreme Court Cases: Chapter 6 Federal Preemption of State Power.

U.S.C. § 1101

Friendly v. Whiting, No. CV 10-1061115, 115 (2010).

8 U.S.C. § 1304(e)

Friendly v. Whiting at 115.

Friendly v. Whiting at 115.

Mary Fan, Post-Racial Proxies: Resurgent State and Local Anti-Alien Laws and Alternate Frames for Antidiscrimination Values. Cardozo L. Rev. 103-104 (2010).

See Friendly v. Whiting

Friendly v. Whiting at 74

United States v. Arizona, No. 10-16645, Brief of Amici Curiae State Legislators for Legal Immigration, 5 (2010).

Gonzalez v. Peoria, 722 F.2d 468, 476 (1983).

U.S. Constitution, Tenth Amendment

Donald E. Lively and Russell L. Weaver. Contemporary Supreme Court Cases: Chapter 6 Federal Preemption of State Power. 28 (2006).

United States v. Arizona, No. 10-16645, Brief of Amici Curiae State Legislators for Legal Immigration, 5 (2010).

8 U.S.C. § 1304(e)

United States v. Arizona, No. 10-16645, Brief of Amici Curiae State Legislators for Legal Immigration, 6 (2010).

Plyler v. Doe, 457 U.S. 202, 225 (1982) (citing De Canas v. Bica, 424 U.S. 351 (1975)).

United States v. Arizona, No. 10-16645, Brief of Amici Curiae State Legislators for Legal Immigration, 7-10 (2010).

Laura Sullivan and Beau Hodai, How Corporate Interests Got SB 1070 Passed, November 9, 2010, available at http://www.npr.org/templates/story/story.php?storyId=131191523

Gabriel J. Chin, et.al., a Legal Labyrinth: Issues Raised by Arizona Senate Bill 1070. Arizona Legal Studies Discussion Paper No. 10-24, 3 (2010).