When Mulugeta Yimer, a taxi driver from
Ethiopia, thought his employer was cheating him several years ago, he did not
complain to the government; he went instead to a worker center called Tenants
and Workers United.

The center helped Mr. Yimer and other drivers
in Alexandria, Va., win the right to keep more of their fares. Not only that,
it has helped child care workers win a 70 percent raise and day laborers win
back pay for minimum-wage violations.

Tenants and Workers United is one of a
fast-growing number of centers that are helping the nation’s 20 million
immigrant workers. In many ways, these centers are doing what labor unions,
fraternal organizations and settlement houses did decades ago for newcomers to
the United States.

"We are all from different countries and
our English is broken and nobody understands us," said Mr. Yimer, who has
driven a taxi for eight years. "But the workers center was willing to
listen to us. They provide us expertise. They provide us a lawyer. They support
us."

There are more than 140 worker centers
nationwide, up from roughly 25 a decade ago. The centers played a pivotal role
in getting tens of thousands of workers to the giant demonstrations seeking a
path to citizenship for illegal immigrants and protesting a House bill that
would turn illegal immigrants into felons.

Some of these centers focus on a particular
nationality, like Korean Immigrant Worker Advocates in Los Angeles and the
Chinese Staff and Workers Association in Manhattan, while some focus on an
industry, like the Mississippi Poultry Workers’ Center and the New York Taxi
Workers Alliance.

Many illegal immigrants — day laborers,
gardeners, laundry workers, restaurant deliverymen — have asked these centers
for help on wage problems because the nation’s legal services offices are
barred from representing them. Moreover, the centers often fill the role once
held by labor unions, which represent less than 6 percent of low-wage workers.

"You have a vacuum created by the
decline of organized labor," said John Liss, executive director of Tenants
and Workers United. "What we’re seeing is a new immigrant working class
creating their own voice."

The centers teach immigrants English and how
to file wage complaints. They have persuaded communities to build shelters for
day laborers, who often stand in the rain and cold without bathroom facilities.
They have helped push for higher minimum wages in several states, and some
centers have won more than $1 million in back pay for immigrants who were
cheated.

"These centers have taken off because
we’re seeing an increase in the number of workers in precarious employment
situations," said Janice Fine, a professor of labor relations at Rutgers
and author of "Worker Centers: Organizing Communities at the Edge of the Dream"
(2006).

"Over the past decade we’ve seen the
biggest influx of immigrants in our nation’s history and at the same time a
decline in resources for wage and hour enforcement at the state and federal
level," Professor Fine said. "These centers have become a safety net
that’s tried to enforce the laws."

Mark Krikorian, executive director of the
Center for Immigration Studies, a group that supports stricter immigration controls, voiced
ambivalence about these centers.

"The bad part is these groups become
lobbies for illegal aliens," Mr. Krikorian said. "On the other hand,
they help people stiffed out of their wages. That can serve a purpose because
it raises the price of hiring illegal aliens, and the more it costs to hire
illegal aliens, the more employers might turn to legal workers."

Many centers survive hand to mouth, relying
on foundation money, government grants, grass-roots fund-raising and, to a
small degree, dues. The Chicago Interfaith Worker Rights Center charges its 150
members $5 each to join.

"These centers have gotten smarter over
the years," said Jennifer Gordon, founder of the Workplace Project in
Hempstead, N.Y., one of the first worker centers. "They are turning
victories that would have just been a back-pay award into something more."

After accusing a chain of sneaker stores of
wage violations, Make the Road by
Walking, based in Brooklyn, helped the
chain’s 95 workers unionize. The Coalition of Immokalee Workers, a
Florida-based group of farmworkers, pressed Taco Bell into making its tomato
growers pay their workers more, and has begun a similar campaign against McDonald’s.
The Restaurant Opportunities Center pressed two fashionable Manhattan
restaurants, Cité and the Park Avenue Cafe, to pay $164,000 in back wages and
give workers three days of sick pay and one week of vacation each year.

At Tenants and Workers United, Sylvia
Portillo, the group’s health coordinator, assists immigrants who ran up large
medical bills when they went to emergency rooms with broken bones or severe
illnesses. Ms. Portillo, a nurse who left El Salvador in the 1980’s, has
persuaded several charities and hospitals to reduce immigrants’ bills.

Each year, she oversees a health fair that
attracts several hundred immigrants who receive free tests for blood pressure,
H.I.V. and diabetes. Similarly, the Taxi Workers Alliance provides free medical
tests to drivers as they wait in line at Kennedy Airport.

"Five years ago everyone went to the
emergency room for everything," Ms. Portillo said. "Now we educate
the people. We tell them the emergency room is only for emergencies, maybe a
broken leg."

Tenants and Workers United has helped
persuade the Alexandria City Council to give Mr. Yimer and other drivers the
right to change taxi companies. The group also persuaded the City of Alexandria
to raise wages for several hundred child care workers, and it has tracked down
employers when immigrants were not paid the promised amount or when their
paychecks bounced.

"Often all it takes is a phone call to
employers to get back pay," Professor Fine said. "Because there is so
little government enforcement in low-wage industries, many employers are
counting on nobody to be there to stop them."

Leaders of many worker centers say they doubt
they will ever achieve sweeping legislative or economic change because their
finances are so weak and because so many of their members are illegal
immigrants who are scared to speak up.

"It’s a mistake to think of the workers
center movement as being a replacement for organized labor," said Bill
Beardall, a co-founder of the Central Texas Immigrant Worker Rights Center in
Austin, Tex., which began as a legal services office that helped farmworkers.

Professor Fine’s research found that ethnic
organizations established one-fourth of the centers, while churches and
religion-based organizations founded another fourth.

The Chicago Interfaith Worker Rights Center
recently helped a Chinese worker who said he had been held in virtual slavery
by a Michigan restaurant, and a Mexican roofer who said his employer left him
for dead in a Dumpster after he fell.

The center has printed brochures in Spanish,
Russian and Polish that tell workers their rights. It also gives leadership
classes.

"We try to get workers to think more
systematically," said Jose Oliva, the center’s executive director.
"That means creating some workers’ organizations that have power and can
negotiate some changes."

The four worker centers in Chicago helped
push through a state law that requires agencies that use day laborers to
register and pay workers’ compensation and unemployment insurance taxes. The
centers also advised a state commission that examined the higher fatality rate
for Hispanic workers.

"These centers
have brought some serious labor violations to the attention of the Department
of Labor," said Esther Lopez, deputy chief of staff to Gov. Rod R. Blagojevich of
Illinois. "Without their help, some of these workers would not come
forward."