On a scorchingly hot desert day last summer, two young humanitarian volunteers working along the Arizona-Mexico border went through their familiar routine of monitoring river washes and makeshift paths on the US side in search of illegal migrants who might be in medical distress after a border crossing that can take as long as three days on foot.
Soon, they came across three men who were vomiting and complaining of gastric pains - apparently because, in their desperation for water, they had drunk out of contaminated cattle tanks. The volunteers, Shanti Sellz and Daniel Strauss, had the men examined by a nurse and a physician at their nearby encampment and decided they needed to be taken to Tucson, the nearest city, for further treatment.
This was nothing out of the ordinary along a highly porous border that has become the backdrop to a new, peculiarly tragic form of Wild West. Record numbers of undocumented Mexicans are making the hazardous journey north across the wilds of the Sonoran desert in search of jobs and a brighter future for their children. And record numbers of them are falling sick and dying because of the punishing conditions - either scorching heat in the summer or bitter night-time cold in the winter.
What happened next, though, was altogether unexpected. Sellz and Strauss were flagged down by the Border Patrol, which not only refused to show the slightest sympathy for the migrants' medical condition but decided that the volunteers themselves should be arrested for aiding and abetting illegal immigration.
Nothing like that had happened in recent memory - in fact, Border Patrol officers have frequently ferried distressed migrants to hospital themselves and so foregone the opportunity to send them back home. But times are clearly beginning to change rather dramatically.
Several months on from their arrest, Sellz and Strauss are about to go on trial on two felony charges - "transportation in furtherance of an illegal presence in the United States" and "conspiracy to transport in furtherance of an illegal presence in the United States". As they contemplate the prospect of potentially lengthy prison terms if convicted, their case has become a microcosm of a highly charged national debate on immigration, one that may well dominate the run-up to next November's mid-term elections.
Every week for the past several weeks, various groups of teachers, environmentalists, doctors, lawyers and elected officials have stood up in a church in Tucson to demand that the charges against Sellz and Strauss be dropped. More than 18,000 people have petitioned the local US attorney to drop the case, arguing that it is an attack on basic human values. "If the government wins this case," the University of Arizona geologist Edgar McCullough told a recent church meeting, "we will be faced with a government-sanctioned policy of killing migrants to enforce our laws."
The prosecuting attorney, however, has been unwavering, and has attracted his own cohorts of supporters - white conservatives who feel the migrants are leeching off their tax dollars and, at the fringes, all sorts of militia figures and would-be vigilantes who have no qualms about cracking down in the name of border security, with an iron fist if necessary.
"I can understand [the volunteers] but I don't think they are helping the migrants," said Glenn Spencer, leader of a well-funded border surveillance group called American Patrol. "In fact they are giving them false hopes, and the help they are offering may well be increasing the risk of people dying."
Such accusations sound only bewildering to the defendants in the case. " Of all the people I've met in the desert," said Sellz, a 23-year-old Iowan who has settled in Tucson to dedicate herself to the group known as No More Deaths, "nobody has ever said they've heard of us. They are stunned to be found. Often they reach out gratefully and say they thought they were done for."
This may be a country of immigrants, but all sides of the political debate now agree the flow of undocumented foreigners has reached crisis point. Activists on the left say the mounting death toll on the border - a staggering 282 bodies recovered this year alone - is entirely unacceptable, especially since the labour the migrants provide is both needed and a backdoor way of keeping costs low for American consumers.
Conservatives, meanwhile, are starting to sound ever more like their European counterparts in calling for a zero-tolerance approach to border policing and warning that the uncontrolled influx of immigrants poses an intolerable threat to the country's financial and cultural well-being.
President George Bush, unusually, finds himself very much on the moderate end of the conservative spectrum. Since the start of his presidency, he has been pushing for an organised guest-worker programme to provide the United States with the labour it needs, and make it much easier for Mexicans willing to do the work to cross the border in more conventional fashion.
The very idea of loosening border restrictions, however, became politically unacceptable in the wake of the 11 September attacks, and Mr Bush has only very recently reproposed his guest-worker project. This time around, though, he finds himself under heavy pressure from his party's right wing, which is positively fuming about immigration. The conservatives have co-opted the language of Mr Bush's war on terror and the notion of a nation under threat from a shadowy foreign enemy, and adapted it to the impoverished Mexicans making their painful way through the desert brush night after night.
Just last Friday, the House of Representatives passed an enforcement bill that would turn undocumented migrants into full-blown criminals, not just violators of immigration law, and called for a fence to be built along the most heavily trafficked sections of the 2,000-mile US-Mexico border.
Mexico's President Vicente Fox immediately likened the plan to the Berlin Wall, and said it was a shameful way for one country to treat a neighbour and partner. The prospects of this becoming law are remote, because of opposition in the Senate and the White House, but such legislation proposals are popping up on almost a weekly basis.
Hardline Republicans want the fence to run all the way from San Diego on the Pacific shores to Brownsville on the Gulf of Mexico. Another wants to send in the military. Yet another is talking about sending all the foreign agricultural labourers home and replacing them with prison inmates. A group of almost 100 Republican members of the House of Representatives, meanwhile, is thinking of ways of ending the automatic right to citizenship extended to anyone born on US soil - something that was enshrined in the constitution at the time that slavery was abolished.
A tough line on immigration is proving to be a vote-winner at election time. Last November, Arizona passed a draconian ballot initiative that, if fully implemented, would deny key public services to undocumented foreigners, including schooling and health care for their children. Candidates in all of the border states are beginning to work immigration into their campaign platforms, and some of the more extreme anti-immigration campaigners are themselves now running for office.
Just last week, the leader of a vigilante group called the Minutemen, Jim Gilchrist, stood in a special congressional election in San Diego, California, and snatched a remarkable 25 per cent of the vote away from the mainstream Republican candidate. Only a few years ago, Gilchrist would have been seen as an extremist on a par with Jean-Marie Le Pen in France.
The changing political mood has had a direct impact on the ground. Although the Border Patrol is itself split between hardline enforcers and some of the older guard who regard their stand-off with the migrants as a slightly absurd game of cat-and-mouse, its funding and resources have been steadily increased over the past couple of years. Out in the borderland brush, one finds brand-new barbed-wire fences and video surveillance equipment. Some heavily frequented spots are also fitted with ground sensors to alert roving patrols.
Much of the pressure on the Border Patrol comes from highly visible activists such as Glenn Spencer of American Patrol, whose house, just a stone's throw from the international boundary about 90 minutes' drive south of Tucson, bristles with surveillance equipment, including satellite transmission receivers, a pair of high-powered binoculars and a spotlight. Spencer, a retired systems analyst for the Pentagon, lives alone with seven Alsatian dogs, which he is training to sniff out human beings much as hunting dogs might sniff out their prey. "We're hunting the most dangerous of all animals - man," he says with a laugh.
Among the gadgets he has developed, and passed on to the Border Patrol, is a 6ft-long unmanned plane equipped with a custom-designed infrared camera as well as a video camera. He and his colleagues are working on a user-friendly Global Positioning System device that would simply give Border Patrol officers the direction and distance of the nearest migrants - or " suspected border intruders", as he prefers to call them.
With his trademark military-style cap and two-way radio always at his hip, Spencer is a man with a single-minded sense of purpose. He wakes up to the sound of the Border Patrol scanner, and spends hours each day monitoring and editing new video footage from his organisation's many hidden cameras. At least one Hollywood producer has invited him to use his footage as the basis of a weekly migrant-hunt series on television.
Spencer is far from a stupid man, and at first the conversation suggests he is not all that far apart from the left-wingers in his analysis of the border problem. He, like them, deplores the creation of a two-tiered society in which undocumented foreigners do the dirty jobs and accept sub-minimum wages to do them. He, like them, wishes the Border Patrol had a more clearly defined role so the country's immigration laws could both make sense and actually be enforced.
But then come the hints of distinctly marginal thinking - including Spencer's firm conviction that the Mexican government is using the migrants in a long-term secret effort to seize territorial control of the United States. "These people are not just looking for jobs, they are looking to make this country part of Mexico," he said.
The fact that such views are now creeping into mainstream discourse speaks volumes about how far the immigration debate has veered to the right in the past decade or so. The heightened immigration flow is not invented - the North American Free Trade Agreement, signed in 1994, has created economic shifts that have encouraged Mexicans either to come north to work in cheap-labour border town factories known as maquiladoras, or to cross directly into the United States. The fact that many of the maquiladoras are now closing under competitive pressure from China has only made the States an even more tempting option.
The fear and hostility, however, seem to be out of all proportion to any threat - economic or other - that the migrants pose. "Every decade or so, we've seen these periods of hysteria emerge over illegal immigration," said Joseph Nevins, a border expert at Vassar College in New York. "It's such easy political hay for politicians, both Republicans and Democrats. Who loses on this? It provides the perfect smokescreen for a whole host of other problems they'd rather not talk about."
It may be no coincidence that the latest wave of anti-immigrant frenzy coincides with the collapse of American aspirations for easy conquest and democratisation in Iraq, and with the more general collapse in the fortunes of the Bush administration. The Republicans, in particular, have become adept at stirring up fears of external threats to win electoral support. Having used Saddam Hussein as their bogeyman in the first Bush term, it now appears they are resorting to Mexican migrants instead.
To the handful of humanitarians who still travel almost daily to the borderlands with water, food and medical supplies and shout out under bridges and along dry riverbeds to see if anyone needs help, this prevailing attitude is deeply disheartening. "They see all these migrants as just clutter, they don't even see them as people," a defiant Shanti Sellz said. "It's blatant racism - fear of the other. That's almost an American value at this point."Reuse content