"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.