"The legislature declares that the intent of this act is to make attrition through enforcement the public policy of all state and local government agencies in Arizona. The provisions of this act are intended to work together to discourage and deter the unlawful entry and presence of aliens and economic activity by persons unlawfully present in the United States."

-- Arizona S.B. 1070, § 1 ("Support Our Law Enforcement and Safe Neighborhoods Act," April 2010)

In September 1957, in a watershed moment in the civil rights movement, Governor Orval Faubus dispatched Arkansas National Guard troops to prevent black students from entering Central High School.

The Eisenhower Administration responded by sending Justice Department lawyers to press for school desegregation, which the NAACP was also seeking in a case that it had brought before the U.S. District Court in Little Rock. The court soon granted the injunction sought by the Justice Department and the NAACP.

A few weeks later, in the face of local resistance edged with hatred and violence, President Eisenhower ordered federal troops to Arkansas to maintain order and safeguard the black school children. The court's preliminary injunction was upheld on appeal, and Central High was eventually desegregated.

The most important legacy of the conflict, however, may have been the images from the streets of Little Rock—of dignified, frightened black students, sturdy federal troops, and a surging, spitting crowd of white protesters.

More than a half-century later, tension between federal and local authorities is again shaping the debate over immigration. An area of law long dominated by the federal government, immigration policymaking and enforcement have witnessed an increasingly vigorous role for state and local authorities in recent years—most prominently in the case of Arizona's strict, new immigration legislation.

It is too early to know whether the heady days of summer 2010 will mark a watershed, like that of Little Rock, in the struggle for immigrant rights, and in the role of the Justice Department in that struggle.

But it is noteworthy that in May, the Justice Department told the U.S. Supreme Court that an earlier, 2007 Arizona law imposing penalties on employers who hire unauthorized immigrants was unconstitutional. The Court agreed to review a challenge to that law and the fate of this statute—referred to by some as the "corporate death penalty" for revoking business licenses of repeated offenders—should be known by June 2011.

Then in July—echoes of the summer of '57—Justice Department lawyers went to U.S. District Court to stop S.B. 1070, Arizona's most recent nativist statute, after the American Civil Liberties Union, NAACP, Mexican-American Legal Defense Fund and others had already commenced litigation.

As summarized by the United States in its brief to the district court, "S.B. 1070 creates new state crimes that penalize an alien's failure to meet federal registration requirements, an alien's unauthorized attempt to solicit work, and the commercial transportation of unlawfully present aliens. And to achieve maximum enforcement of its new immigration policy, S.B. 1070 establishes a new state-wide mandatory immigration status-verification system to be employed whenever practicable by every law enforcement officer who, during the course of a stop, has reasonable suspicion of a person's 'unlawful presence.'"

This last item prompted many to refer to S.B. 1070 as Arizona's "papers, please" law. The district court granted the Justice Department's request for a preliminary injunction against the core provisions of S.B. 1070.

A separate Justice Department investigation of allegations of widespread racial profiling and illegality in the office of Joe Arpaio, Sheriff of Maricopa County, is ongoing.

And, in a further echo of the heartbreaking courage displayed by the young adults who attempted to integrate Central High in '57, the summer of '10 also witnessed widespread protests by undocumented high school and college students, many brought to the United States as infants.

These young adults declared their unauthorized status to political leaders and the media, risking deportation even while insisting on their moral claim to full and equal membership in society. No image from these protests has yet achieved the iconic, conscience-provoking status of the photographs from Little Rock, but the movement is yet young.

Finally, as September began, the U.S. Court of Appeals for the Third Circuit invalidated a Hazelton, Pennsylvania ordinance similar to the Arizona provision now at issue before the Supreme Court, in a sweeping 188-page opinion authored by Chief Judge Ted McKee.

Later that month, Senate Majority Leader Harry Reid announced plans to add the DREAM Act, which would allow many undocumented students to regularize their status, as an amendment to the Department of Defense appropriation bill, a "must-pass" bill.

Amidst all this activity, the most aggressive anti-immigrant state or local measure remains Arizona's S.B. 1070.

Like Orval Faubus before her, Governor Jan Brewer of Arizona has appealed the court order enjoining S.B. 1070. She has sounded "law-and-order" themes (even asserting, and then disavowing the claim, that illegal immigration has left headless corpses scattered along the Arizona side of the border), and insisted on the right of her state to conducts its own affairs.

Like Eisenhower, President Obama has announced he will send troops to Arizona—though Obama's troops will be deployed at the border, and not to defend immigrants from vigilante violence in the streets of Maricopa County.

The struggles today in Arizona, Hazelton, and elsewhere do not occur in a vacuum, of course, but rather play out in the context of the United States' historic immigration law and policy. Nor is the specific dispute in Arizona—the proper role, if any, for state and local actors in making or enforcing immigration law—new. Episodic clashes between federal and local authorities have long characterized the history of American immigration laws.

Early Origins: Acadians and Naturalization

Two founding-era debates illustrate that disagreements about more versus less restrictive immigration and naturalization policies, and about the optimal degree of local autonomy in a system of national immigration rules, date to the very beginnings of the nation.

1. Acadian refugees.

One immigration event that likely shaped views of the founding generation was the Acadian refugee crisis of the late 1750s. French Catholic settlers in the Canadian Maritime Provinces, the Acadians became subjects of Great Britain under the Treaty of Utrecht.

Yet, the Acadians refused to swear allegiance to Britain, and as a result, their formal citizenship status was ambiguous. Many British authorities and American colonists considered the Acadians foreigners—"French" or, at best, "French neutrals."

Weary of Acadian resistance to English rule, in 1755 British troops launched a brutal campaign to deport thousands of Acadians, driving them off their lands, burning their former villages, and removing the Acadians to the American colonies to the south.

The response of the colonies to this early refugee crisis varied, however. Massachusetts and Pennsylvania, for instance, enacted legislation that would allow Acadian children to be forced into indentured servitude. One Acadian petition in Pennsylvania sought mercy, explaining that Acadians would be "the most unhappy People that ever appeared, if, after having lost what God had given us, for the Subsistence of our Families, we see ourselves forced to tear our Children from the Arms of our tender Wives."

Elsewhere, colonial authorities physically detained the Acadians and contemplated expelling them. The British delivered many of the most dangerous Acadians to South Carolina, for instance, where at first local authorities refused to allow the refugees to land.

The Governor suggested re-settling the Acadians on islands off the South Carolina coast, "where little Huts may be put up for them" and cattle and rice supplied, until further instruction from the Crown "or some legal & effectual Method be thought of to get clear of them." Eventually the Governor agreed to send the most dangerous Acadians up the coast to North Carolina and Virginia, and negotiated legislation with the Assembly to indenture some Acadians and release others for resettlement.

An absence of uniform state-level (or sub-federal) responses to the perceived burdens of new immigrants; frustration with the immigration policies of a national sovereign; fear, animus, and mistreatment directed towards immigrant families; and a local desire literally to drive away unwanted newcomers—all of these impulses, evident in Arizona today, would have been familiar to the founding generation and are reflected in the colonial responses to Acadian refugees in the late 1750s.

2. The Meaning of Naturalization.

"Citizenship" was an unsettled notion in the colonial era and did not operate to demarcate rights as sharply as it does in the contemporary period. Under colonial laws, for instance, noncitizens were frequently eligible to vote.

And while colonists generally considered themselves subjects of Britain, "subjectship" law in the colonies diverged from that in Britain. In particular, colonial naturalization policies began to reject concepts of natural and permanent allegiance in favor of volitional and contractual principles of citizenship.

British restraints on naturalization and on immigration to the American colonies is listed as one of the grievances in the Declaration of Independence, where the colonists complained that the King "has endeavoured to prevent the Population of these States; for that purpose obstructing the Laws for Naturalization of Foreigners; [and] refusing to pass others to encourage their migration hither . . . ."

The Articles of Confederation allowed each state to legislate its own naturalization statutes, resulting in significant variation. James Madison described this checkerboard of state rules as "a fault in our system, and as laying a foundation for intricate and delicate questions."

By operation of the privileges and immunities clause, however, all states were obligated to respect the rights of the "free inhabitants" of other states. Resentment soon blossomed within restrictionist states opposed to the more generous laws of other states, especially Pennsylvania, which was alleged to have "receive[d] all that would come there . . . at the expense of religion and good morals."

There was little debate at the Constitutional Convention and during the ratification period over the desirability of substituting a single national naturalization rule for the varied state laws. Even Anti-Federalists agreed that the state-level naturalization experience had been disasterous.

This consensus was reflected in the text of the Constitution, which empowers Congress to "establish an uniform Rule of Naturalization . . . throughout the United States." It is also apparent in early Supreme Court decisions, such as Chief Justice Marshall's declaration in 1817, "That the power of naturalization is exclusively in congress does not seem to be, and certainly ought not to be, controverted."

In other words, the Framers deliberately drafted the Constitution to grant the naturalization power to the federal government, based on the widespread view that in this area, disuniform state regulation under the Articles of Confederation had failed.

The Development of the Modern Immigration Regime

Congress launched the beginnings of our modern immigration regime in the post-Civil War period.

The Reconstruction Congresses expressed concern for the mistreatment of immigrants in their debates on the Thirteenth Amendment "involuntary servitude" clause, the Anti-Peonage Act of 1867, the Civil Rights Act of 1870, and the Padrone Act of 1874—particularly Chinese immigrants in the western United States, Mexican immigrants in the southwest, and even Italian children in the eastern cities.

Soon thereafter, however, Congress began to enact laws directing the exclusion at ports of entry of certain undesirable persons, and later, the deportation, or removal from within the country, of others.

Many of these early grounds for federal exclusion or deportation reflected the same concerns as prior state laws with poverty, disease, and criminality. Other federal laws became explicitly racial, initially targeting Chinese, Japanese, and other Asian nationals, but eventually establishing national origins quotas and discriminating against Mexican and other Latino nationals as well.

As Congress moved to legislate immigration laws in the late nineteenth century, legal challenges to the residual state measures, as well as to various procedural and substantive features of the new federal laws, arose. The Supreme Court soon decided in favor of federal power to regulate immigration, held that this power was exclusively federal, and invalidated state laws.

In Chy Lung v. Freeman, for example, the Court considered a California statute that permitted state officials to examine new immigrants arriving at its ports, and to impose a significant bond if the state examiner concluded that the immigrant was within any one of numerous classes of undesirable persons. In 1875, the Supreme Court struck down the California statute, explaining: "The passage of laws which concern the admission of citizens and subjects of foreign nations to our shores belongs to Congress, and not to the States."

Similar language appears in dozens of judicial opinions in the ensuing century. With the expansion of the federal immigration apparatus in the late nineteenth and early twentieth centuries, backed by Supreme Court decisions such as Chy Lung v. Freeman, the role of individual states in developing or implementing immigration policy rapidly diminished.

The full history of federal immigration law, from its late nineteenth century origins to the modern twenty-first century conflicts, is beyond the scope of this essay. That history, however, has reflected periods of high legal immigration, including in the "Ellis Island" era at the start of the twentieth century; admission of large numbers of temporary workers, such as during the "bracero" programs of the 1940s and 1950s; and large-scale unauthorized migration, as in the 1990s.

It has also included periods of intense nativism; ideological persecution of labor activists and political radicals in the 1920s and during the McCarthy era; explicit racial exclusions, including Chinese exclusion, the long era of national origins quotas, and ineligibility to citizenship for many Asian immigrants; and discriminatory enforcement against disfavored immigrant groups, from Japanese internment to the mass deportation of bracero workers and the express targeting of Arab, Muslim, and South Asian immigrants after the September 11 terrorist attacks.

These developments in immigration law have all occurred at the federal level. Throughout the decades, while state or local officials have occasionally been conscripted to assist in federal implementation, there has been little direct role for states in immigration policy-making.

Today's immigration regime is codified primarily in the Immigration and Nationality Act (INA), adopted by Congress in 1952 and frequently amended since, especially in 1965, 1986, and 1996.

In the course of crafting the INA, Congress has reflected the post-Civil War understanding that immigration regulation is an exclusively federal function, and has occasionally legislated narrow and explicit derogations from the otherwise muscular preemption of state or local laws.

None of these exceptions, however, authorize the sort of laws and practices that have cropped up in places like Arizona.

For instance, Congress has expressly authorized direct enforcement of two criminal immigration provisions. One provision of the INA prohibits the smuggling, transporting, or harboring of illegal immigrants; another, entitled "Authority to Arrest," empowers INS agents "and all other officers whose duty it is to enforce criminal laws" to make arrests for those violations.

In other words, Congress expressly authorized all those empowered to enforce criminal laws—including state and local police—to make arrests for smuggling, transporting, and harboring offenses.

The legislative history of the provision confirms its plain meaning. When first drafted, the provision allowed officers "of the United States" to arrest alleged smugglers. Congress's elimination of the limiting phrase "of the United States" was intended to expand enforcement authority by allowing all criminal law enforcement officers—federal, state, or local—to make arrests for smuggling, transporting or harboring illegal immigrants.

It makes sense specifically to authorize local police to enforce those specific provisions only in a world in which police are otherwise prohibited from such enforcement. And as the Supreme Court has repeatedly reminded litigants, Congress does not intend any of its statutes to be superfluous, and thus each provision must be read to have new and definite meaning.

In 1996, Congress enacted amendments authorizing state and local police to arrest a second set of immigration violators, those who have committed the criminal offense of illegal reentry following a prior deportation.

The 1996 measure expressly provides that "state and local law enforcement officials are authorized to arrest and detain an individual who (1) is an alien illegally present in the United States, and (2) has previously been convicted of a felony" and ordered deported.

Representative John Doolittle offered a floor amendment that became this provision. He explained that "the Federal Government has tied the hands of our State and local law enforcement officials," because "current Federal law prohibits State and local law enforcement officials from arresting and detaining criminal aliens whom they encounter through their routine duties." His amendment, he argued, would "untie the hands of those we ask to protect us," at least with respect to previously deported felons who have illegally reentered the country.

Congress has also long understood that local police enforcement of civil immigration law is broadly preempted, unless expressly authorized by Congress. One section of the INA, first enacted in the 1950s, confers emergency powers on the Attorney General to authorize "any State or local law enforcement officer" to enforce federal immigration laws in the event the Attorney General certifies that there exists "an actual or imminent mass influx of aliens arriving off the coast of the United States, or near a land border."

And in 1996, Congress added non-emergency procedures for state and local jurisdictions to enforce federal immigration laws, in INA section 287(g). This provision requires training of state or local police, execution of a written agreement, and close oversight by federal immigration authorities.

As of 2010, over 70 jurisdictions have entered into "287(g) agreements" with federal authorities. More importantly, these twin procedures—the emergency "mass influx" procedures and the ordinary "287(g)" process—suggest that immigration laws may be enforced by state and local police only as legislated by Congress and subject to federal training, supervision, and oversight—and not at the unilateral initiative of local jurisdictions.

In other words, in the second half of the 20th century, Congress has approved state and local enforcement of specified immigration crimes, and broad civil enforcement if done pursuant to detailed statutory procedures. Each of these provisions was enacted on the understanding that only the federal government can make or enforce immigration laws, and each represent a narrow but explicit departure from that principle.

The Contemporary Period

While the twentieth century was largely a time of ascendant federal authority over immigration, and diminishing state and local participation, the past decade looks different.

The federal regime, creaky and out-of-date, has endured. The Department of Homeland Security has become today the largest federal law enforcement agency, with skyrocketing budgets and new records for arrests, detentions, and removals set virtually every year.

At the same time, however, there has been an undeniable explosion of immigration-related policymaking at the state and local level. Punitive measures such as those adopted in Hazelton, Pennsylvania and in Arizona have received much of the media attention.

Some local integrationist strategies, such as municipal confidentiality or non-cooperation orders regarding immigration enforcement, or New Haven's Elm City Resident Card (an optional municipal identification card), have provoked local controversy. Still other inclusionary approaches, many modest or incremental (such as a town hall offering some of its materials in languages other than English), have become common but do not always attract the same public scrutiny.

What explains the growth of state and local measures, and the wildly divergent approaches adopted by communities across the country? And given the longstanding history of federal supremacy in immigration policy and enforcement, are they likely to survive and flourish? Four primary factors explain the current turmoil.

First is a general trend toward devolution, visible across government programs affecting immigrants and predating the most recent events.

For instance, in 1996, Congress enacted a major overhaul of welfare programs. [Please read this Origins article for more on Welfare Reform in the 1990s] When Congress could not resolve a disagreement about immigrant eligibility for the major cooperative federal-state programs, such as Medicaid and Temporary Assistance to Needy Families (TANF), and subject to a few federal limitations, it largely punted to the states, authorizing each to determine for itself whether large classes of foreign nationals would be eligible for those programs.

Thus, in the late 1990s, when all state legislatures had to rewrite their own welfare laws in response to vast federal changes, they also were forced to legislate in historic detail regarding a long list of particular immigration statuses, mapping those onto state, local, and cooperative federal-state programs.

Similarly, state criminal justice systems have been increasingly forced to confront the consequences of immigration status at arraignments, plea hearings, sentencing, and during probation. This trend dramatically intensified in the aftermath of the Supreme Court's 2010 decision in Padilla v. Kentucky that a criminal defense lawyer's failure to advise her client of the immigration consequences of a plea may constitute ineffective assistance of counsel. This ruling is likely to result not only in numerous vacated convictions of non-citizens, but also to reforms in all fifty states regarding the role of judges in state criminal courts when accepting plea agreements (by which the overwhelming majority of criminal prosecutions are resolved).

The 2002 Supreme Court decision, Hoffman Plastic Compounds, Inc. v. NLRB, concerning the rights of undocumented workers under federal labor laws, has also forced many state labor and worker compensation agencies to engage more deeply than previously in the intersection of labor and employment law with immigration status.

Second is demography. While not reaching historic peaks as a percentage of the population, legal and unauthorized migration in the last twenty years has been high. More importantly, in the 1990s, new immigrants moved beyond the traditional "receiving" states such as California, Texas, Florida, and New York, to other states. And within all states, they moved beyond the largest cities to suburban and rural communities, many of which had not experienced significant new immigration in nearly a century.

The arrival of new, largely Spanish-speaking Latino immigrants caused local frictions in communities where, at least initially, mediating religious, business, and other civic institutions often did not yet exist.

At worst, members of some such communities reacted with racism and nativism; at a minimum, the reality of new immigrant populations in such towns compelled public institutions such as police departments, public schools, hospitals, and libraries to adapt their practices to address the reality of these new residents.

And it is these sort of local adaptations, from Hazelton's effort to penalize landlords who rent to immigrant tenants, to the Houston Police Department's non-cooperation policy and New Haven's municipal ID, that have often sparked local controversies, protests, and lawsuits.

Third is September 11. Following the terrorist attacks, the U.S. Department of Justice rescinded a prior Office of Legal Counsel memo concluding that local police lacked authority to engage in civil immigration enforcement. Despite enactment in 1996, not one local jurisdiction had executed a 287(g) agreement by 2001. After the attacks, the Justice Department encouraged jurisdictions to carry out this type of agreement.

It began entering tens of thousands of administrative immigration warrants into the FBI's National Crime Information Center database, through which local police conduct records checks on millions of motorists, arrestees, and others they encounter every day. And it began an aggressive, public campaign to persuade local law enforcement officials to make civil immigration enforcement part of their routine duties, even without a formal agreement.

The Bush Administration argued that civil immigration enforcement was a national security imperative, and sponsored programs that increased state and local participation in immigration enforcement after September 11—a trend with a few exceptions that the Obama Administration has largely continued and even intensified.

Fourth is the absence of meaningful federal reform to our immigration laws, which remain rooted in a post-WWII model that is out of step with our current economic and security needs, and inconsistent with our moral values.

Polls indicate that a significant majority of the American public support immigration reform built on the three pillars of 1) legalization for some but not all of the current undocumented population; 2) expanded but not unlimited opportunities for future, lawful immigration, both to reunify families and through temporary worker programs; and 3) more effective enforcement of the resulting immigration order.

These three principles were also the foundation of bipartisan discussions in the Senate in 2006-07. In the absence of federal legislative action, however, states and localities have had no choice but to undertake their own diverse efforts to adapt local rules to the demographic realities of their communities.

Where will this lead?

I expect that many of the most punitive local measures, like Arizona's S.B. 1070 and the Hazelton ordinance, will be struck down by the courts as preempted by federal law. By this time next year, the Supreme Court will have decided the "corporate death penalty" case from Arizona, and this opinion will no doubt shape the legal and policy landscape, especially in other states considering their own S.B. 1070s.

More inclusionary local measures have rarely been challenged in court, by contrast, and the few suits initiated have generally failed. Thus I expect that communities inclined in this direction will continue to pursue integrationist policies.

More broadly, the state and local debate about appropriate policies towards new residents that is as old as the Acadian refugee crisis of the 1750s will surely endure. Yet this very local friction and debate will likely continue to contribute to the pressure on Congress to modernize our antiquated immigration statutes, in ways that reflect the center of public opinion: some legalization, some enhanced "future flows," and meaningful enforcement of laws capable of being carried out.

Years from now, I expect it will be difficult to explain to our children and grandchildren why for decades this nation countenanced the de jure subjugation of millions of immigrants, benefiting from their labor, while forcing them to live a life in the shadows, members of a reviled caste, denied their full human flourishing.

And in that context, even in the centuries-long debate about the content of our immigration laws and the role of state and local governments in carrying them out, the conflicts of the Summer of '10 may well turn out to look a lot like those of the Summer of '57 for civil rights.