It is labor's biggest priority for the new administration: changing federal law to make it easier for workers to unionize -- and win contracts with their employers.
Unions, which spent an estimated $450 million to help elect Barack Obama to the presidency and put more Democrats in Congress, want the Employee Free Choice Act passed quickly to begin to reverse decades of declining membership.
The U.S. Chamber of Commerce has vowed to spend $10 million to defeat the bill.
Obama's selection of union-friendly Rep. Hilda L. Solis (D-El Monte) as Labor secretary is seen as good news for the bill's advocates. She has called it "vital legislation."
Everyone agrees that the fight will be in the Senate, where the measure died last year after passing easily in the House.
Both sides plan to run grass-roots campaigns in key states and have begun airing TV ads, to "educate" the public.
The most controversial provision would require employers to recognize a union once a majority of workers signed membership cards, in what is known as a card-check system.
Companies can, but rarely do, recognize unions under those circumstances. Instead, they typically exercise their right to require an employee election organized by the National Labor Relations Board.
Trauma nurse Sherwood Cox, who worked to defeat two California Nurses Assn. drives at Western Medical Center Santa Ana, said that under the proposed law, he would be unable to keep the union out.
"When it's actually gone to vote, we've gone into the ballot booth and we've voted no," Cox said. "Both times, the union was totally shocked that they lost."
Under the card-check system, an employer could be surprised to learn that the workplace has gone union overnight.
Business leaders have couched the fight in terms of workers' privacy rights.
"The American public supports the secret ballot," said Randy Johnson, a vice president of the U.S. Chamber of Commerce. "Card checks are subject to abuse."
An ad produced by the bill's opponents features an actor from the HBO series "The Sopranos" portraying a mobster-like labor organizer threatening a worker to sign a union card.
"They're manipulating that," complained Josh Goldstein, spokesman for American Rights at Work, a nonprofit group that backs the bill. "Our battle right now, before we even get to the horse race on Capitol Hill, is how do we get people talking about this bill the way they should be?"
