Peter Costantini/IPS - "It’s a mighty hard row that my poor hands have hoed. My poor feet have traveled a hot, dusty road. Out of your dust bowls and westward we rode. Your deserts were hot and your mountains were cold." So sang troubadour Woody Guthrie of Great Depression-era refugees fleeing the Dust Bowl for California.

Today, another massive river of migrants is flowing across the United States, but this time northward from Mexico. An estimated half-million undocumented Mexican workers enter the U.S. annually, and many have traveled back and forth numerous times.

All along the path of immigration and return, the human and civil rights of the newcomers are increasingly jeopardised by the failure of the U.S. government to reform what many agree is a broken immigration system.

Along the 3,168-kilometre border between the U.S. and Mexico, beefed-up immigration enforcement and extended fences have channeled increasing numbers of migrants away from settled areas and out into the deserts and mountains. There, their safety and even lives are menaced by unforgiving terrain and weather — and sometimes by drug and human smugglers.

According to Mexican legislator Edmundo Ramírez, 498 people have died this year attempting to cross the border.

The high death rate for immigrants is one of numerous human rights violations documented by the Border Network for Human Rights (BNHR), a consortium of community committees along the border. A report by the group says that "a dangerous anti-immigrant sentiment and an increased militarisation of the border region" threaten the rights to life, liberty, privacy, security and equality before the law.

The magnet for nearly all immigrants is plentiful jobs. Those who successfully run the gauntlet, or merely overstay a temporary visa, can earn many times what they could south of the border.

According to international and U.S. law, all workers have certain rights regardless of immigration status. But immigrants have faced an increasingly hard time enforcing workplace rights in an atmosphere of xenophobia, weak labor laws and lax enforcement.

Highly publicised workplace raids over the past year have targeted immigrants without papers, but arrested and intimidated many legal immigrants and U.S. citizens as well.

In November, the Department of Homeland Security (DHS) abandoned a plan to send out "no-match letters" requiring employers to penalise or fire workers whose Social Security numbers didn’t match those in a government database. Labour and civil liberties groups charged that flaws in the database would result in the firing of many legal immigrants and citizens, and discrimination against those who look or sound "foreign".

"What’s remarkable is how many undocumented workers are organising despite the [George W.] Bush administration’s focus on deporting people," law professor Jennifer Gordon of Fordham University told IPS. She singled out an organising campaign by the United Food and Commercial Workers at the Smithfield Packing Company, the world’s largest pork-processing plant, in the southeastern state of North Carolina.

Immigration raids have decimated the workforce and the company has used intimidation and violence to avoid unionisation, according to the non-governmental Human Rights Watch.

Yet over 1,000 workers walked off the job last year to protest the firing of 50 employees who could not produce legal documentation. Within a few days, management rescinded the firings and allowed more time to produce the documents.

"That’s a testament to those workers’ bravery, to the union’s tenacity, and to the fact that even in the worst circumstances people will eventually stand up for their rights," said Gordon.

In the East Coast city of Baltimore, a local workers’ centre recently won a living wage under a city ordinance for the low-income day labourers who clean the baseball park, Camden Yards. The United Workers Association organised on a platform of human rights for all workers in a successful effort to forge unity among the largely African-American and Latino immigrant workforce.

"I’ve wandered all over this green growing land," sang Guthrie. "Wherever your crops were, I’ve lent you my hands. On the edge of your city you’ll see me and then, I come with the dust and I go with the wind."

Farm workers, who are primarily Latino immigrants in much of the country, are excluded from the National Labour Relations Act, and therefore denied many labour rights.

During the wildfires in southern California this fall, discrimination against migrant labourers threatened their right to life. Although a residential neighbourhood in the San Diego area was mandatorily evacuated, ABC News reported that the owner of a farm right across the street pressured his workers to keep picking tomatoes. Workers donned dust masks and kept working out of fear of losing their jobs, until local and Mexican officials convinced the owner to let them leave without retaliation.

Even legal immigrants in the H-2 guest worker programme are routinely cheated out of wages, held virtually captive by employers, and forced to live in squalid conditions, according to a report by the Southern Poverty Law Centre. Congressman Charles Rangel called the programme "the closest thing I’ve ever seen to slavery". A bill known as AgJobs under consideration by Congress seeks to reform the guest worker programme and offer farm workers a path to citizenship.

In the communities where immigrants live, many don’t feel safe even in their own homes. Pre-dawn raids by armed agents of Immigration and Customs Enforcement (ICE) have terrorised Latino families, many of whose members are citizens or legal immigrants.

When local officials complained, an ICE official told the New York Times, "We don’t need warrants to make the arrests." In response, immigrant families in New York, Tennessee and Texas are suing ICE for violating their rights.

"The Fourth Amendment guarantees to each of us the sanctity and dignity of our homes," said Patrick Gennardo, attorney for the plaintiffs in one case.

Some cities and states have passed anti-immigrant laws denying services to undocumented immigrants or penalising landlords who rent to them or merchants who sell to them. Other ordinances have tried to curb day labourers who gather on street corners to seek work, or have declared English the only official language.

Immigration is generally a federal responsibility, however, and many local laws have been challenged on this basis. Other localities have defeated anti-immigrant measures. Some cities, including New York, San Francisco and Seattle, have even adopted sanctuary policies under which local officials do not participate in immigration enforcement.

In 1948, Guthrie sang of Mexican migrant workers: "Some of us are illegal, and some are not wanted, our work contract’s out and we have to move on. Six hundred miles to that Mexican border, they chase us like outlaws, like rustlers, like thieves."

At the end of the road, during detention and deportation, the rights of migrants continue to be trampled. Human Rights Watch (HRW) urged the government to improve medical treatment for immigrants in detention, particularly those with HIV/AIDS. "Immigrants are getting poor care, are suffering, and, in some cases, have died," a representative of the group said.

HRW also criticised the U.S. for "harsh and inflexible deportation policies" that violate the human rights of families. Long-time legal residents are often summarily deported for minor infractions, the group said. Many families have been forced apart: the group estimated that the 672,593 immigrants deported for crimes since 1996 left behind at least 1.6 million spouses and children, many of whom are U.S. citizens.

Last year, ICE deported a record 195,000 people.