The case could be tied up in the courts for awhile, leaving supporters of the law simmering in frustration.
Arizona Senate Bill 1070 was signed in late April and takes effect July 29 -- unless it's suspended in federal court. The American Civil Liberties Union has filed a civil rights suit against the measure and has issued widespread warnings about traveling to Arizona.
"You know, we saw Eisenhower send in federal troops to Little Rock to integrate the schools -- this is on an order of magnitude that the federal government says, 'The states can't do this," said San Diego's ACLU director, Kevin Kennana.
The Arizona law has ignited sporadic protests in San Diego, as well as resolutions of censure and economic boycotts by municipalities throughout California. The law would require Arizona police to question -- and potentially arrest -- illegal immigrants while officers are enforcing other laws such as traffic stops, and legal immigrants are required to carry their documentation.
The U.S. Justice Department is challenging the measure on grounds that it usurps the federal government's authority over immigration matters.
Local backers of the law, including Peter Nunez, a former U.S. Attorney for San Diego, said it's entirely consistent with federal immigration statutes that Uncle Sam has failed to enforce.
"It's just a complete travesty that the federal government would interfere with a state that is trying to protect its own interests, since the federal government won't do that," said Nunez, who is currently an activist affiliated with the Federation for American Immigration Reform.
A number of states with significant immigration issues are closely watching the legal developments surrounding Arizona's law.
For its part, the Obama Administration has been touting "comprehensive" immigration reform. Critics, though, argue that the proposed White House policy is really a smokescreen for an amnesty that would legalize the residency of 12 million people who violated the law coming to the U.S.