In recent years it [Arizona] has barred illegal immigrants from receiving government services, from winning punitive damages in lawsuits and from posting bail for serious crimes. A new state law shuts down businesses that hire illegal workers. And the sheriff of Maricopa County, which includes Phoenix and three-fifths of the state’s population, dispatches his deputies and volunteer “posses” to search for illegal street vendors or immigrants being smuggled through the county.

“What I love about what Arizona is doing is we don’t have to rely on the federal government,” said state Rep. Russell Pearce, a Mesa Republican who has authored most of the toughest measures. “It has truly woken up the rest of America that states can fix that problem.”

The campaign has had an effect: Illegal immigrants complain it’s impossible to find good work and are leaving the state.

…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.