Union membership dropped last year to the lowest level since the 1930s.
Government figures released Wednesday showed union membership declined from 11.8 percent to 11.3 percent of the workforce, another blow to a labor movement already stretched thin by battles in Wisconsin, Michigan, Indiana and other states to curb bargaining rights and weaken union clout.
Overall membership fell by about 400,000 workers to 14.4 million, according to the Bureau of Labor Statistics.
More than half the loss came from government workers.
In Indiana, where a new right-to-work law took effect last March, the state lost about 56,000 union members. The law prohibits unions from requiring workers to pay union fees, even if they benefit from a collective bargaining agreement. Michigan lawmakers approved a similar measure in December.
Another problem for unions is an aging membership that is not being replaced by younger members.