Arizona lawmakers have passed the nation's toughest immigration law and sent it to the governor.
Supporters say it will stop a growing crime wave at the border, but civil rights groups claim it's racial profiling.
Groups protesting at the state capitol don't like the bill, which would make it a crime for illegal immigrants not to have alien documents and would give police authority to question suspected illegals.
It would also give jail time to those harboring or concealing illegal immigrants.
That concerns many American Hispanics.
"You are driving around looking over your shoulder wondering if police are looking at you because of the color of your hair or skin," Arizona resident Carlos Savala said.
The bill also bans day laborers from gathering on street corners.
"It could be the single most anti-immigrant bill the country has seen in a generation," Chris Newman with the National Day Labor Organization said.
But the murder three weeks ago of cattle rancher Rob Krentz by suspected illegal aliens, has raised both anger and fear that the border situation is out of control.
Senator John McCain said that of the 600,000 people apprehended at the Arizona border, more than one in six had already committed crimes in Arizona.
"So we're not talking just about people who are crossing our border to go to work," McCain said. "We are talking about criminal elements that are increasingly sophisticated in their operations, they are more heavily armed, and they present a great challenge to our law enforcement people in our state."
McCain and his fellow Senator John Kyl want Washington to send 3,000 National Guardsmen to the border.
"People are fed up. And the government hasn't done what it needs to do to solve this problem." Kyl said. "And when you leave a big vacuum like that, is it any wonder then that people in Arizona, in the state legislature for example, decide well then we've got to do something about it?"
The bill is now on the desk of Arizona's Republican Governor Jan Brewer. But she has not said whether she will sign it.