Amid news of desert killings on the border and Mexican kidnapping rings, Arizona became the first state to pass comprehensive anti-illegal immigration laws that challenged not only federal jurisdiction over immigration but also basic constitutional rights of non-citizens living in America.
After Gov. Jan Brewer in April 2010 signed Senate Bill 1070 into law, polls showed widespread support in Arizona and elsewhere for the state crackdown, which included the ability of police to demand suspects they deemed "reasonably suspicious" show legal immigration papers or face arrest.
The Obama administration immediately challenged it in federal court, saying its "papers, please" requirement and its overall intrusion into federal jurisdictions made it unconstitutional and could violate people's civil rights by profiling them by their skin color.
After protests and boycotts, a federal judge granted an injunction against the key part of the law a day before it was to take effect. In February 2011, Arizona countersued, claiming the US government had failed to control the state's border with Mexico. In April 2011, the US Ninth Circuit Court of Appeals upheld the earlier ruling against the state.
"The Arizona statute before us has become a symbol," Ninth Circuit Judge John Noonan wrote. "For those sympathetic to immigrants to the United States, it is a challenge and a chilling foretaste of what other states might attempt."
The case has been appealed to the US Supreme Court, though the high court has not yet indicated whether it will take the case.