By KRIS MAHER (Wall Street Journal) 23 JAN 2010

Organized labor lost 10% of its members in the private sector last year, the largest decline in more than 25 years. The drop is on par with the fall in total employment but threatens to significantly limit labor's ability to influence elections and legislation.

On Friday, the Labor Department reported private-sector unions lost 834,000 members, bringing membership down to 7.2% of the private-sector work force, from 7.6% the year before. The broader drop in U.S. employment and a small gain by public-sector unions helped keep the total share of union membership flat at 12.3% in 2009. In the early 1980s, unions represented 20% of workers.

Labor experts said theunion-membership losses would have a long-term impact on unions and their finances, because unions wouldn't automatically regain members once the job market rebounded. In many cases, new jobs will be created at nonunion employers or plants.

"The bad news for unions is twofold. When times are bad they lose members, and when times are good they don't recoup those members," said Gary Chaison, a professor of industrial relations at Clark University in Worcester, Mass.

The manufacturing sector and construction industries—both of which tend to be heavily unionized—were hit particularly hard in the recession by the credit crisis and global downturn, which damped demand for industrial goods. Private sector construction lost 237,000 union members, while manufacturing lost 253,000 union members, representing more than half of the loss of private-sector union jobs.

The report caps a week of bad news for organized labor, as Democrats lost a filibuster-proof majority in the Senate, dashing union hopes for passing legislation to ease union-organizing rules, and putting the union-backed health-care bill into question.

Unions also suffered a big setback with a Supreme Court decision on campaign financing that removed limits on corporate spending. While unions are also free of certain limits, companies and business groups could outspend labor in the future.

Some labor experts said labor's focus on politics came at the expense of organizing. "It's a year when the labor movement focused its energies on labor-law reform and health care," said Kate Bronfenbrenner, a Cornell University labor expert.

With those issues on shaky ground, unions are now expected to focus their political energy on job creation, in hopes that new jobs will be union jobs.

"We're focusing on job creation," said Josh Goldstein, a spokesman for the AFL-CIO. "And we need to make sure that workers have the ability to bargain and make sure those jobs are good jobs."

Write to Kris Maher at kris.maher@wsj.com

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