By Sam Hananel

Associated Press

WASHINGTON (AP) — Union membership plummeted last year to the lowest level since the 1930s as cash-strapped state and local governments shed workers and unions had difficulty organizing new members in the private sector despite signs of an improving economy.

Government figures released Wednesday showed union membership declined from 11.8 percent to 11.3 percent of the workforce. Overall membership fell by about 400,000 workers to 14.4 million, according to the Bureau of Labor Statistics. More than half the loss, about 234,000, came from government workers including teachers, firefighters and public administrators.

But unions also saw losses in the private sector even as the economy created 1.8 million new jobs in 2012. That membership rate fell from 6.9 percent to 6.6 percent. Job growth generally has taken place at nonunion companies.

“To employers, it’s going to look like the labor movement is ready for a knockout punch,” said Gary Chaison, professor of industrial relations at Clark University in Worcester, Mass. “You can’t be a movement and get smaller.”

Union membership was 13.2 percent in 1935 when President Franklin D. Roosevelt signed the National Labor Relations Act. Labor’s ranks peaked in the 1950s, when about 1 of every 3 workers was in a union. By 1983, roughly 20 percent of U.S. workers were union members.

Losses in the public sector are hitting unions particularly hard because that has been one of the few areas where membership had grown over the past two decades. About 51 percent of union members work in government, where the rate of union membership is 37 percent, which is more than five times higher than in the private sector.

Dwindling membership means unions carry far less influence than they used to in setting a benchmark for wages and benefits that might be followed at nonunion companies. Unions are already gearing up to defeat Republican governors in Ohio, Michigan, Florida, Pennsylvania, and Wisconsin, where they fear more anti-union measures could crop up soon.

Among full-time wage and salary workers, union members in 2012 had median weekly earnings of $943, while those who were not union members earned $742.