"The more important thing is how the chief of a law enforcement agency chooses to enforce the law," Dupnik said. For example, other counties do immigration sweeps, but not his, he said.

"Law enforcement did not ask for this law," Dupnik said. "Law enforcement did not need this law."

Santa Cruz County Sheriff Tony Estrada said the validated portion of the law marked "very little change" for his department. His county shares a 50-mile border with Mexico and is a major corridor for smuggling of drugs and illegal migrants.

His 39 officers will continue to call any of the 1,000 U.S. Border Patrol agents in his county to conduct immigration checks, he said. "Our concern is the public perception of what we are doing," he said. He fears Latinos won't ask for help and witnesses won't come forward, he said.

"The Hispanics will look at us a little differently, and that concerns me," Estrada said.

Merchants and residents of the Latino community reported anxiety and fear among clientele and neighbors.

Phoenix taqueria owner Hector Manrique said Tuesday that business has been dropping since the law was proposed in 2010; he predicted it will get worse now that the Supreme Court has ruled.

"It's bad for the Hispanic community," said Manrique, a native of Mexico who has been in Phoenix since 1990 and has run the Taqueria Guadalajara since 2003.

"It seemed like everybody kind of forgot about it for a little bit and now, all of a sudden, I've got friends who were talking to me yesterday, and they're pretty scared because they've got kids, they've got family to support."

Kelly Ramirez, 31, of Tucson, a real estate broker and business owner, said many Latino immigrants don't know the details of the law, but they do know something has changed.

"They can't really look into it, so what they'll do is they'll hide," she said. "There's going to be less conversation, less help from individuals that maybe aren't doing anything wrong but know of somebody that is."

Russell Pearce, the former Republican state senator who authored SB 1070 and then was ousted from office in a recall election in his suburban Phoenix district last year, told CNN Tuesday that accusations of possible racial profiling were "demeaning to law enforcement."

"An officer is trained to pay attention to things that don't fit. All this bill does is allow them to ask the questions they need to ask," Pearce said.