In the current hotel conflict, most attention has focused on the proposed contract length and the dispute over who pays health-care benefits. But another issue also separates the two sides -- civil rights and the relationship between African American and immigrant workers.

For a decade, San Francisco's Unite Here Local 2 and Local 11 in Los Angeles have proposed and won language in their contracts protecting members from discrimination and firing because of immigration status. This reflects the important role immigrant workers play in the union. On San Francisco picket lines, voices speak in accents from Mexico and Central America, the Caribbean, China, the Philippines and a host of other countries. In San Francisco, as in many other big U.S. cities, immigrants make up a majority of the hotel workforce.

Last year, Unite Here brought black civil-rights veterans together with immigrants on the Immigrant Workers Freedom Ride to push for immigration reform that would make it easier for immigrant workers to join unions, go on strike and advocate for their labor rights.

This year, Locals 2 and 11 added new language to their existing contract proposals on immigrant rights, and the hotels agreed. But the Multi-Employer Group, the hotel owners' bargaining collective, didn't accept a related proposal asking the hotels to set up a diversity committee and hire an ombudsman to begin increasing the percentage of African-American workers.

The proposal stems from an effort by the union to address the changing demographics of the hotel workforce. In the city's hotels, the percentage of African American workers is falling, as employment continues to grow. African Americans now make up less than 6 percent of the San Francisco hotel workforce, a number that has declined in each of the past five years but one, employer reports show.

In San Francisco, this issue has a lot of history. The Palace Hotel, where workers are now locked out, was the scene of one of the city's most famous civil-rights demonstrations. In 1963, civil-rights activists sat in, and were arrested, in the hotel lobby, as they demanded that management hire blacks into jobs in the visible front-of-the-house locations, where the color line had kept them out. Richard Lee Mason, an African-American banquet waiter at the St. Francis, remembers, "African Americans had been kept in the back of the house for far too long. People wanted to be in the front of the house, and rightly so."

Employment prospects improved for black workers for some years, but the situation changed by the 1980s. Hotels hired increasingly higher percentages of immigrants, in a move they hoped would create a less demanding and expensive workforce. "I suspect that because the industry had had a great struggle with African Americans, they thought we were too aggressive," Mason speculates. "A lot of us had come out of the civil-rights movement, and we were willing to fight for higher wages and to make sure we were treated fairly. "

Steven Pitts, an economist at the Center for Labor Research and Education at UC Berkeley, says Mason's experience was not uncommon. "This perception by employers of African-American workers is true nationwide," he says. "Blacks aren't perceived as compliant, and therefore when many employers make hiring decisions, they simply don't hire them."

If the hotel industry hoped its new immigrant workforce would be more compliant, however, those hopes were not realized. Immigrants proved to be as militant as the workers who came before -- 36 of the city's big hotels were struck in 1980, and smaller strikes took place in the following two decades. But black employment at the hotels fell nonetheless.

The union's civil-rights proposal "is an important first step," according to Pitts, "in addressing this problem. But in the civil-rights movement we learned we need structural change that can bring [black and other] community residents into the hotels, and make sure they progress" to better jobs.

Winning that kind of structural reform would take a lot of bargaining power -- an important argument for coordinated negotiations in cities such as Los Angeles and San Francisco. By putting the demand on the table, even if the goal is still a long way off, Unite Here may gain the support, in today's strike, of African-American and other communities who feel excluded from hotel employment.

This makes the union part of a new civil-rights movement, geared to a changed world of globalization, in which millions of immigrants fleeing war and poverty have become an important part of the U.S. workforce, especially in service industries. They now encounter discrimination like that faced for years by longtime residents, especially African Americans. Instead of competing for jobs, workers could identify with each other in an effort to protect the rights of all. The key is prohibiting discrimination against immigrants because of their legal status, while enforcing affirmative action to gain more jobs for underrepresented communities.

David Bacon, a reporter and photographer who specializes in labor issues, is author of "The Children of NAFTA" (University of California Press, 2004).