No one knows how many immigrants have left the state, and the most recent government figures show Arizona growing robustly -- as of July, Maricopa was the fastest-growing county in the nation.
But enough immigrants have left that the government of Sonora, the Mexican state bordering Arizona, has complained about how many people have arrived on its doorstep.
Pearce says the overall effect has been undeniably positive for Arizona. "Smaller class sizes, shorter emergency room waits," he said. "Even if [illegal immigrants] are paying taxes -- and most of them aren't -- the cost to taxpayers is huge."
The biggest effect has come from the new employer sanctions law, which took effect in January.
The law is fairly straightforward.
Any business caught hiring illegal immigrants is put on probation. If it is caught doing the same thing again, the state revokes its business license.
The only defense for an employer is if it used E-Verify, a federal pilot project to allow businesses to confirm the legality of their laborers.
The law did what it was supposed to with Jorge Hernandez, a 32-year-old illegal immigrant from Mexico. He had been working in a Phoenix tire shop for years when in December his bosses told him they'd have to let him go because of the new law. Now he struggles to support his family by working as a day laborer and is thinking of leaving.
"I've been in Arizona for 11 years," he said. "This is the worst one. For those years I worked every day. I had money, I had a car."
Hernandez dreams of moving to New Mexico, where friends have told him the economy is stronger and sentiment against illegal immigrants weaker. "They don't have E-Verify there," he said in Spanish.
E-Verify has at least one significant flaw -- its treatment of naturalized U.S. citizens.
Between October 2006 and March 2007, about 3,200 foreign-born U.S. citizens were initially improperly disqualified from working by E-Verify. Their status was later corrected.
Because many did not register their citizenship with the Social Security Administration, they are often listed as possible illegal workers.
That's what apparently happened to Ochoa, 47, who became a citizen in 2000. He quit his job as a car salesman at the end of last year and got hired by a local Dodge dealership in February. Days later, his new employers called him with bad news -- E-Verify classified him as a possible illegal immigrant. He only had a couple of days to convince Social Security that he wasn't.
