Monday’s 5-3 decision in Arizona v. United States striking down most of Arizona’s immigration law has been well covered (see the on-line symposium hosted by SCOTUSblog). But, I have not seen any coverage of a puzzling cite in Justice Scalia’s much-discussed dissent. Justice Scalia would have upheld all of Arizona’s law, seemingly on the basis that states are sovereigns who have “power to exclude from the sovereign’s territory people who have no right to be there.” Scalia viewed the law of naturalization as separate from the law of immigration and explained that Congress’s control over immigration did not need to be set forth as a separately enumerated power because a “sovereign nation” has inherent power “to forbid the entrance of foreigners within its dominions.” To support this proposition, Scalia cited Article I, section 9, clause 1: “The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the year …” (slip opinion at 7). The clause is one of a few in the Constitution that prohibited Congress from outlawing slavery before 1808. Despite avoidance of the word “slave,” this is not a hidden meaning. Why would Justice Scalia choose this pernicious cite to support inherent immigration authority for both the federal government and the states? He cannot have intended to equate immigration with importation of slaves. Thoughts?