In one Arizona county alone, Yuma County, the sheriff estimates that law enforcement agencies would spend between 775,880 and 1,163,820 dollars in processing expenses. Jail costs would run between 21,195,600 and 96,086,720 dollars, and attorney and staff fees between 810,067 and 1,620,134 dollars.

The estimates by Yuma County Sheriff Ralph E. Ogden were produced because there is no state-wide fiscal data yet available on the cost of the legislation’s implementation. Sheriff Ogden’s estimates were prepared for inclusion in a fact sheet produced in response to similar legislation in 2006.

Yuma County is one of Arizona’s 15 counties, with a population of about 200,000. The sheriff’s fact sheet also shows that additional detention facilities would have to be built at unknown costs.

These costs do not account for lost revenue such as tax contributions and consumer purchasing, as well as the potentially expensive lawsuits that will likely ensue.

Republican Governor Jan Brewer signed the legislation after a week of rallies and protests by anti- and pro-immigration groups. The new law makes Arizona the first state in the nation to deem it a crime for a person to be an undocumented immigrant.

Several legal challenges to keep the legislation from taking effect are already in the works by the Mexican American Legal and Educational Fund, the American Civil Liberties Union and the National Day Labourer Organising Network.

“Arizona would have the same place in history as South Africa,” said Salvador Reza, organiser for the PUENTE movement, which advocates for human rights, comparing the new law to apartheid.

But the passage of the Arizona law may also have ignited new energy and resolve from the pro-immigration reform movement.

President Barack Obama has criticised the Arizona bill, saying it threatens to “undermine basic notions of fairness that we cherish as Americans, as well as the trust between police and our communities that is so crucial to keeping us safe.” He called on Congress to enact comprehensive immigration reform.

Sen. John McCain, a Republican of Arizona, has in the past been one of the champions of comprehensive immigration reform. Today, locked in a tight primary challenge from his right wing to win his party’s nomination for another term, he has endorsed the new law. Arizona’s other senator, Republican John Kyl, has done likewise.

Known as the “Support Our Law Enforcement and Safe Neighbourhood Act”, the law would allow police officers to arrest a person based on “reasonable suspicion” that he or she is an undocumented immigrant. Police departments could face lawsuits by individuals who believe they are not enforcing the law.

A coalition of businesses and religious leaders has warned that the impact of the new measure could severely damage Arizona’s economy.

The new law “is tearing our state into two. It humiliates us into the eyes of America and threatens our economic recovery,” said Phoenix Mayor Phil Gordon.