Every few weeks Bob Heilig, a 67-year-old Arizona rancher, rounds up the Mexican cattle that have strayed over the border onto his land and herds them back to their rightful owners through the fence he calls “the taco curtain.” We are about 50 feet north of the Mexican border at the edge of Heilig’s Double Bar R Ranch, 70 miles south of Tucson. We are also at the point where the border fence, 18 feet of concrete-reinforced steel, simply stops for a while. “It’s a real hilarity, isn’t it?” Heilig says as he parks his Nissan Frontier atop a low, sandy knoll in the Sonoran Desert. To the west, looking like the Great Wall of China and about as successful at repelling invaders, the wall undulates over rolling hills at a cost of $5.4 million per mile toward the border town of Nogales. To the east, it becomes a single chest-high railroad rail and an Old West–style barbed-wire fence—not much of a change since John Wayne rode through these parts making Red River in the late 1940s.

Bob and his wife, Eileen Whalen, bought their ranch in 2004, near the height of the huge northward migration. The seller warned them, but couldn’t hand it over fast enough. For Eileen and Bob, a fourth-generation Arizona rancher who joined the Army at 17 and was gone for 41 years, coming home was the fulfillment of a long-held wish. They built their dream house in 2008, a promise from Bob to Eileen, who commutes from Seattle, where she is the executive director of Harborview Medical Center.

Heilig shows us where he pries the barbed wire back to shoo the Mexican cattle through. “The fence is the biggest joke in the world,” he says. “This huge, immense thing that cost millions, and then four-strand barbed-wire fence. You look at it and go, Huh?”

When you try to understand Arizona’s dysfunction—and maybe, God forbid, America’s—you have to start at The Fence and the grand self-delusion that the border could be fortified enough to keep out the invading brown horde. An ugly symbol of a frightened nation, it has fooled no one, except perhaps the politicians in far-off Washington who built it and made it their proxy for immigration reform. But it has barely slowed the Mexicans who’ve climbed over it, dug under it, cut through it, or, as on Heilig’s ranch and elsewhere, simply walked around it. To be sure, the numbers of undocumented border crossers are down, from more than a million a year to a few hundred thousand. It took the Great Recession to stifle the northward migration. The flow of drugs, on the other hand, continues unabated; America’s demand is insatiable and the fence has barely slowed the smugglers.

Now as Washington finally turns to immigration reform, Heilig has no illusion that President Obama’s plan to overhaul the immigration system—or the slate of congressional alternatives—is going to make much difference for the ranchers who live along the border. The key component of the various proposals includes offering a way for some 11 million illegal immigrants to become citizens, which has been the sticking point that stalled reform for decades.

“The big debate will be about what to do with the people living in the United States today,” he says. “But it doesn’t really address the issue of people coming across. I don’t understand why they don’t deal with that.”

Arizona accounts for 380 miles of the 2,000-mile Mexican border, and through three presidential administrations, it has been the primary route through which the lion’s share of undocumented migrants and illegal drugs flow. As President Bill Clinton sought to cool the more politically vocal California in the early 1990s, it was a border crackdown there that inadvertently funneled migrants into the inhospitable deserts and mountains of Arizona. As the numbers of border crossers multiplied in the American economic boom, fencing out the Mexicans became the only politically palpable “solution.” Border fortification snowballed in the wake of 9/11, when President George W. Bush doubled the size of the Border Patrol and signed on to erect 670 miles of fence in strategic stretches along the border. More than a billion dollars were spent on high-tech gadgetry and a “virtual” fence that was supposed to “see” border crossers in the desert. Among its many malfunctions, the virtual fence confused raindrops and cows with migrants and was eventually scrapped.