United States v. State of Arizona, 703 F.Supp.2d 980 (D. Ariz. 2010)

(plaintiff challenged the constitutionality of defendant's enforcement of S.B. 1070 which codifies federal law provisions concerning illegal immigration into state law to give state enforcement authority in lieu of plaintiff's longstanding failure to enforce federal provisions; plaintiff claims that power to regulate illegal immigration is an exclusively federal issue and that the provisions of S.B. 1070 are pre-empted by federal law; plaintiff, in the alternative, sought injunction against enforcement of S.B. 1070 pending trial on the merits; court holds that defendant's attempt to support federal effort to control illegal immigration (which is a joint federal/state effort) via S.B. 1070 should be enjoined pending full trial on merits even though plaintiff had abandoned rather than pre-empted field; no discussion of public interest).