Today’s immigration decision in Arizona v. United States amounted to another nail in the coffin of federalism. Scalia, in his dissent, explained how the decision has abrogated state sovereignty (citations removed for readability):

The United States is an indivisible “Union of sovereign States.” … Today’s opinion, approving virtually all of the Ninth Circuit’s injunction against enforcement of the four challenged provisions of Arizona’s law, deprives States of what most would consider the defining characteristic of sovereignty: the power to exclude from the sovereign’s territory people who have no right to be there. Neither the Constitution itself nor even any law passed by Congress supports this result. I dissent.

As a sovereign, Arizona has the inherent power to exclude persons from its territory, subject only to those limitations expressed in the Constitution or constitutionally imposed by Congress. That power to exclude has long been recognized as inherent in sovereignty…

…There is no doubt that “before the adoption of the constitution of the United States” each State had the authority to “prevent [itself] from being burdened by an influx of persons.” … And the Constitution did not strip the States of that authority. To the contrary, two of the Constitution’s provisions were designed to enable the States to prevent “the intrusion of obnoxious aliens through other States.” …The Articles of Confederation had provided that “the free inhabitants of each of these States, paupers, vagabonds and fugitives from justice excepted, shall be entitled to all privileges and immunities of free citizens in the several States.”… This meant that  an unwelcome alien could obtain all the rights of a citizen of one State simply by first becoming an inhabitant of another. To remedy this, the Constitution’s Privileges and  Immunities Clause provided that “[t]he Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States.” … But if one State had particularly lax citizenship standards, it might still serve as a gateway for the entry of “obnoxious aliens” into other States. This problem was  solved “by authorizing the general government to establish a uniform rule of naturalization throughout the United States.” … In other words, the naturalization power was given to Congress not to abrogate States’ power to exclude those they did not want, but to vindicate it.

Scalia goes on to explain how opposition to the Sedition Act demonstrated doubt on the federal government’s role, but none whatever regarding the State power to control immigration, before offering:

In light of the predominance of federal immigration restrictions in modern times, it is easy to lose sight of the States’ traditional role in regulating immigration—and to over look their sovereign prerogative to do so. I accept as a given that State regulation is excluded by the Constitution when (1) it has been prohibited by a valid federal law, or (2) it conflicts with federal regulation—when, for example, it admits those whom federal regulation would exclude, or excludes those whom federal regulation would admit.

Possibility (1) need not be considered here: there is no federal law prohibiting the States’ sovereign power to exclude (assuming federal authority to enact such a law). The mere existence of federal action in the immigration area—and the so-called field preemption arising from that action, upon which the Court’s opinion so heavily relies, ante, at 9–11—cannot be regarded as such a prohibition.We are not talking here about a federal law prohibiting the States from regulating bubble-gum advertising, or even the construction of nuclear plants. We are talking about a federal law going to the core of state sovereignty: the power to exclude. Like elimination of the States’ other inherent sovereign power, immunity from suit, elimination of the States’ sovereign power to exclude requires that “Congress . . . unequivocally expres[s] its intent to abrogate,” …Implicit “field preemption” will not do.

…And it is an assault on logic to say that identifying a removable alien and holding him for federal determination of whether he should be removed “violates the principle that the removal process is entrusted to the discretion of the Federal Government,” … The State’s detention does not represent commencement of the removal process unless the Federal Government makes it so.

But that is not the most important point. The most important point is that, as we have discussed, Arizona is entitled to have “its own immigration policy”—including a more rigorous enforcement policy—so long as that does not conflict with federal law. The Court says, as though the point is utterly dispositive, that “it is not a crime for a removable alien to remain present in the United States,” … It is not a federal crime, to be sure. But there is no reason Arizona cannot make it a state crime for a removable alien (or any illegal alien, for that matter) to remain present in Arizona.

…The State’s whole complaint—the reason this law was passed and this case has arisen—is that the citizens of Arizona believe federal priorities are too lax. The State has the sovereign power to protect its borders more rigorously if it wishes, absent any valid federal prohibition. The Executive’s policy choice of lax federal enforcement does not constitute such a prohibition.

He  then concludes powerfully (emphasis mine):

…The President said at a news conference that the new program is “the right thing to do” in light of Congress’s failure to pass the Administration’s
proposed revision of the Immigration Act.7 Perhaps it is, though Arizona may not think so. But to say, as the Court does, that Arizona contradicts federal law by enforcing applications of the Immigration Act that the President declines to enforce boggles the mind.

…As is often the case, discussion of the dry legalities that are the proper object of our attention suppresses the very human realities that gave rise to the suit. Arizona bears the brunt of the country’s illegal immigration problem. Its citizens feel themselves under siege by large numbers of illegal immigrants who invade their property, strain their social services, and even place their lives in jeopardy. Federal officials have been unable to remedy the problem,and indeed have recently shown that they are unwilling to do so. Thousands of Arizona’s estimated 400,000 illegal immigrants—including not just children but men and women under 30—are now assured immunity from enforcement, and will be able to compete openly with Arizona citizens for employment.

Arizona has moved to protect its sovereignty—not in contradiction of federal law, but in complete compliance with it. The laws under challenge here do not extend or revise federal immigration restrictions, but merely enforce those restrictions more effectively. If securing its territory in this fashion is not within the power of Arizona, we should cease referring to it as a sovereign State. I dissent.