by Jeff Tyler

Anyone working in the U.S. needs at least a visa to do so legally. But there’s no such requirement for joining a union.

“For unions to organize workers, they can’t ask to see their green card first and then have them sign a union card second. They seek to organize everyone in a workplace, whatever their immigration status,” says Harley Shaiken, a professor at U.C. Berkeley specializing in labor issues. “Many of these industries that have a lot of immigrant workers are vital for the growth of unions.”

Labor leaders voice other motivations.

Ana Avendano with the AFL-CIO says the new law could have a chilling effect on worker complaints.

“Our employment laws rely on workers to file complaints with the government to expose dangerous workplaces, non-payment of wages, discrimination, and other violations of law,” says Avendano.

She says the Arizona law could be used to bust unions. When faced with a picket line, Avendano says, employers could just call the sheriff and have their problems deported.