Miles Locker, an attorney with the California Labor Commissioner's office, said that the ruling would not limit the state's ability to collect wages for work that was performed, if, for example, an employer routinely paid less than the minimum wage. However, the state would no longer be able to protect workers who are fired after complaining about such wage violations or other abuses.
"It's a problem because it leaves undocumented workers vulnerable to discharge for doing those things that they have every right to do," he said. "It tends to encourage the most unscrupulous employers to only hire undocumented workers and then fire them when they try to assert their rights."
Rodriguez and others, however, said the decision could also galvanize support for a new legalization program for illegal immigrants, which the AFL-CIO has advocated for two years.
"It's a slap in the face by a Supreme Court that made an ideological decision," said Eliseo Medina, a vice president of the Service Employees International Union and a leading proponent for a new amnesty program. "I've been getting calls all day from people saying we really need to step up our campaign. Everyone's reaction is one of anger. We are, and should be, outraged."
In Los Angeles, activists working to improve pay and conditions for garment and restaurant workers and day laborers said they hope state agencies will interpret the decision narrowly, pertaining only in the case of union-organizing campaigns.
"We're trying to look at this as optimistically as possible and move these cases forward," said Victor Narro of the Coalition for Humane Immigrant Rights of Los Angeles. "If somebody does decide to go to court on this [issues not involving union campaigns] it could get kicked back to the Supreme Court."
Unions and activists have long complained of employers using immigration laws to intimidate and fire assertive workers. Although undocumented workers are rarely reinstated, state and federal agencies have often awarded back pay when the firing was deemed illegal.
Savage reported from Washington and Cleeland from Los Angeles.