PHOENIX — The frustration had long been building in Arizona, with every drug-related kidnapping, every home invasion, every "safe house" discovered crammed with illegal immigrants from Mexico.
The tensions finally spilled over this month with passage of the nation's toughest law against illegal immigration, a measure that has put Arizona at the center of the heated debate over how to deal with the millions of people who sneak into the United States every year.
A number of factors combined to produce the law: a heavily conservative Legislature, the ascent of a Republican governor, anger over the federal government's failure to secure the border and growing anxiety over crime that reached a fever pitch last month with the slaying of an Arizona rancher, apparently by an illegal immigrant.
"The public wants something done. They're tired of it," said state Sen. Russell Pearce, who sponsored the legislation. "They've seen the ineptness and the malfeasance on the part of the government, and they're frustrated."
The new law makes it a state crime to be in the United States illegally and directs police to question people about their immigration status if there is reason to suspect they are illegal.
Critics warned that the law could result in racial profiling and other abuses. A legal challenge and a November referendum are planned to overturn it.
Supporters of the law view it as a commendable effort to combat what is fast becoming a scourge in the United States.
Arizona is the biggest gateway into the United States for illegal immigrants. The state is home to an estimated 460,000 illegal immigrants — a population larger than cities such as Cleveland, St. Louis and New Orleans.
The Republican-dominated Legislature has backed a series of tough immigration measures in the past decade, only to have the most aggressive efforts thwarted by then-Gov. Janet Napolitano, a Democrat.
But the political stars aligned this year for the GOP. President Barack Obama appointed Napolitano to his Cabinet, clearing the way for Republican Secretary of State Jan Brewer to take over as governor.
The GOP made a headlong rush back into the immigration debate, and Brewer signed the bill last week.