Nearly half a million passengers have been delayed or stranded since a pilots' sickout at the nation's No. 2 airline began a week ago.

And while passengers fumed Friday over the Allied Pilots Association action to protest the airline paying some pilots less than others, unionists and others pointed out this was evidence of a stronger labor movement rebounding from a two-decade decline.

Contrary to popular belief, union membership is actually growing and public support for organized labor is more than many people think.

"American business keeps underestimating the labor movement," said Kate Bronfenbrenner, director of Labor Education Research at Cornell University.

"They say: 'There's an economic boom, everyone's happy, unions are no longer appropriate or relevant.'"

But she believes this view is wrong as society evolves from one based on labor-intensive heavy manufacturing industries to a 21st century civilization of high-tech services.

Just as companies have adjusted to the changing times, so have unions, Bronfenbrenner told Reuters. They are becoming more focused and efficient in an effort to rid themselves of the old image of militancy and corruption.

Government labor statistics show the number of union members in the United States rose by 100,000 last year to 16.2 million — the first increase in five years. However, the percentage of the total U.S. workforce that is unionized slipped from 14.1 to 13.9 percent.

"It's partly economic we're doing so well," said AFL-CIO spokeswoman Lane Windham. "There have been lots of new jobs added. And unions are more involved in recruiting new members.

"We had not been organizing well, but it's changing now under (AFL-CIO) President (John) Sweeney," Windham said. "The goal is to hold elected officials accountable and to get employers to allow workers to organize."

One problem, she said was that "labor laws are stacked against organization in the workplace.

"The right to organize is a constitutional right and too many times it has only been seen as an employer's right instead of the workers'. We want companies to follow the law."

The relevant law, The Wagner Act, was passed in 1936 during the Great Depression and replaced the National Industrial Recovery Act of 1933, that was earlier ruled unconstitutional.

The Wagner Act restated many of NIRA's provisions and established the legal basis for unions.

Citing studies by the AFL-CIO, which represents 72 major U.S. unions, Windham said roughly half the working people polled said they would choose to join a union. "If there are no threats to fire them, we see lots of support for unions."

Cornell's Bronfenbrenner agreed. "Look at the UPS strike last year, the public sided 2-to-1 with the unions, according to our polls. People had thought they would be very angry they couldn't send their packages."

She also cited a Bell Atlantic strike over contracting-out issues. "When they see temporary and part-time jobs and no good benefits or jobs not protected, people are asking, 'Well who is benefiting from this economic boom? It's not us.'"

"Public sympathy is crucial, especially when they face a hostile government and labor laws," said Bronfenbrenner.

Besides recruitment, unions are also concerned with issues of pay and benefits and the increasing practice of contracting out work or making positions temporary or part-time. "Although there has been an uptick in wages, they are still not at the same level as in the '70s," said Windham.

"People are having a hard time raising families. Even though the economy is up, a lot of the new jobs are not good jobs. We campaigned for a minimum wage, now we're pressing for a living wage."

Bronfenbrenner said as corporations become more international, there is a need for unions to form alliances with foreign workers and become more strategic, getting to understand not only members' needs, but also those of management and shareholders and politicians.

During a recent rubber workers' dispute at Bridgestone-Firestone, workers contacted fellow workers around the world, using the Internet to win support through e-mail campaigns and "cyber-picketing" she said.