The story of the border wall originally aired Oct. 27 on VICE News Tonight on HBO.

When Chris Cabrera joined the U.S. Border Patrol in 2003, the job involved cruising through vast open stretches of the Rio Grande Valley trying to catch drug smugglers and migrants coming across the Texas-Mexico border. Three years later, the United States began building a fence that was supposed to keep these people out and make his job easier. It quickly became obvious it wasn’t going to work.

“We came with this 18-foot wall, and the very next day they had 19-foot ladders,” Cabrera recalled recently. “It got to the point where we had so many ladders at the station that they told us to stop bringing the ladders in. It was just insane the number of ladders we had. Hundreds upon hundreds.”

Watch the full VICE News Tonight segment:

One of the key promises of Donald Trump’s presidential campaign is to build a bigger, better wall along the entire 1,933-mile border with Mexico, a wall that’s “impenetrable and beautiful.” The Republican nominee says the barricade will halt the northward flow of both immigrants and drugs. His supporters are enthusiastic about the idea, and Republicans made building a border wall a key tenet of the party’s official platform this year.

As Trump noted during the final presidential debate, Hillary Clinton has also supported creating a physical barrier between the U.S. and Mexico: She was one of 25 Democratic senators to vote for the Secure Fence Act of 2006. Clinton has promised in this campaign to implement comprehensive immigration reform, and she has also said the U.S. needs “to have secure borders, and what that will take is a combination of technology and a physical barrier.”

But people who actually live along the border in the Rio Grande Valley are extremely skeptical. Border Patrol agents like Cabrera, local police, elected officials, and people who live with the existing wall in their backyards say it has been an epic boondoggle. Seemingly everyone in the area agrees that any plan to build a new wall or expand the existing fence is a bad idea.

“It’s a waste of money, period,” said Cameron County Sheriff Omar Lucio, whose jurisdiction sits opposite Matamoros, one of the most dangerous corners of Mexico. “It’s not going to work. I don’t care what [Trump] is saying.”

In Texas, the existing fence — or wall, depending on your definition of the term — mostly consists of rows of cube-shaped, rust-colored posts that stand about 20 feet tall. The columns are spaced about four inches apart, too narrow for even a child to squeeze through. But the fence abruptly ends in some places, leaving vast open stretches. In the most absurd cases, 30-foot sections of fence are surrounded on both sides by miles of wide open space.

Trump’s plan to overhaul the barrier has been short on specifics. (A campaign spokesperson did not respond to multiple requests for comment.) At various times over the past year, he said the wall would rise between 35 and 55 feet high and cost about $8 billion to $12 billion. Other estimates have put the cost at $25 billion. Trump insists Mexico will foot the bill — Mexico has said it won’t — but even if all goes according to his plan, there’s ample evidence to suggest the wall would do nothing to stop drug smuggling, one of his stated goals.

The Rio Grande Valley is one of the busiest smuggling hubs on the Mexican border. Border Patrol agents in the area seized 516,664 pounds of marijuana in 2015, second only to the agency’s Tucson sector, and 1,809 pounds of cocaine, the most of any sector in the continental U.S. Altogether last year, the Border Patrol seized more than 1.5 million pounds of weed, 11,220 pounds of cocaine, 8,282 ounces of heroin, and 6,443 pounds of meth. Still, those totals are likely just a fraction of the illicit drugs entering the U.S.

Construction of the wall here, long a dream project of Republicans and border hawks, was initiated by President George W. Bush initiated in 2006 when he signed the Secure Fence Act. The resulting fence, which cost more than $15 million per mile in some places and $6 billion total, now spans approximately 650 miles of the U.S.-Mexico boundary. Bush said the fence would “help protect the American people” and “make our borders more secure,” but even combined with cameras, drones, sensors, and other surveillance technology, the wall isn’t working.

Part of the problem is that Texas has 1,254 miles of border but only about 100 miles of wall. The Secure Fence Act set out to establish “operational control” over the border, not to seal off the entire thing. The Department of Homeland Security opted to focus on fencing off the border around populous places, hoping to force migrants and smugglers into remote areas with rough terrain, where it’s more difficult to cross. The agency also decided to create gaps in the fence, with the intention of funneling illegal crossers into places where, in theory, the Border Patrol would be waiting.

Another problem is basic geography. The winding path of the Rio Grande River makes building a wall complicated, and the current fence more than a mile north of the river in places. Much of the land — about two-thirds of the border, according to a Government Accountability Office report — is privately owned by U.S. citizens. Some of these border-property owners have been trapped in a no-man’s land where their homes and property lie south of the wall but are still within the boundaries of the United States.

“My son-in-law says we live in a gated community,” jokes 88-year-old Pamela Taylor. Born in England, Taylor met her Mexican-American husband during World War II and homesteaded along the Rio Grande near Brownsville in 1946. Her charming old ranch house sits near a bend in the river, and the wall cuts diagonally across the adjacent farmland before looping further south.

Taylor says she’s witnessed smugglers throwing bags of “dope” over the fence to people waiting on the other side, who pick up the bundles and drive off. She claims she once found a duffel bag with 40 kilos of marijuana stashed in the bougainvillea flowers in her front yard, and she started leaving out coolers filled with water and soft drinks to discourage thirsty migrants from breaking into her house. She also keeps a shotgun, a bulletproof vest, and a Border Patrol hat hanging outside her bathroom as a deterrent.

“This wall, in my opinion, is not doing one iota of good,” Taylor said. “Number one, it’s a fence, not a wall, and there are gaps all the way along… my land is used as a funnel, so people coming over go through my property to get through one of those gaps.”

There are at least 13 large gaps in the Rio Grande Valley fence, according to a map created in 2014 by the Center for Investigative Reporting. Completing the wall would require prolonged and costly court battles with property owners like Eloisa Tamez, who lives east of Taylor near San Benito, Texas. Tamez’s land along the Rio Grande has been in her family since the late 1700s. She lost a two-year legal fight with the government in 2009 over construction of the wall, which now sits about 30 feet behind her house.

Tamez’s family used to farm the land that is now on the other side of the wall, and she has fond memories of picnics down by the riverbank. In order to access most of her property now, she has to drive a half-mile down the road to pass through a motorized gate, which can be opened with a key code.

Tamez noted that many farms in the area now have similar gates, and she pointed out that the code can be easily passed around among workers, who could share it with drug smugglers or coyotes. “Just imagine,” she said. “One compadre gives it to the next one and the next one, and before you know it, so many people have it. What’s secure about that? It’s just a waste of money. It’s laughable.”

Even if the gate codes were closely guarded secrets, the wall is easily surmountable. South of McAllen, Texas, along the border with the Mexican city of Reynosa, Scott Nicol, an opponent of the border wall and the co-chair of the Sierra Club’s Borderlands Team, points to a section of wall where he routinely finds makeshift ladders that have been piled up on the U.S. side by the Border Patrol.

“I think there’s some guy with a shop near the river and he just bangs out ladders all day long,” Nicol said. “The Border Patrol piles ’em up, the county hauls ’em off to the dump. It’s been the cycle of the wall for years.”

Cabrera, the Border Patrol agent, says he’s seen smugglers easily scale the wall even without the help of a ladder. In January, a Mexican TV network filmed two men with large vacuum-sealed packages strapped to their backs scaling the wall. When the men realized they were being filmed by a news crew, they fled back across the border. It took them about 43 seconds to shimmy up and over.

“That’s like ‘American Ninja Warrior ‘ — I mean that’s some crazy stuff,” Cabrera said. “They get up over that wall in a hurry.”

Cabrera is the vice president of the Rio Grande Valley chapter of the Border Patrol union, which recently endorsed Trump on the strength of his promise to secure the border. He said drug cartels will also use migrants to create a diversion, sending large groups — including families — directly into the hands of the Border Patrol to tie up resources. “That pulls a lot of agents from the outlying areas to deal with what we call babysitting duties,” he said.

Beyond old-fashioned technology like ladders, smugglers have been caught using a drone, a catapult, and a homemade cannon to launch drugs over the wall. Sinaloa Cartel boss Joaquin “El Chapo” Guzman is infamous for tunneling beneath the wall, and the DEA reports that federal authorities have detected more than 75 cross-border smuggling tunnels in the last five years, mostly in California and Arizona.

But even the most imposing wall would do nothing to stop the vast majority of drugs from entering the U.S. According to the DEA’s 2015 National Drug Threat Assessment, Mexican cartels send “the bulk” of their drug shipments over the border through legitimate points of entry, hidden in vehicles or disguised as commercial freight. Tens of thousands of trucks and $1 billion in trade come across the U.S.-Mexico border daily, and there’s no way to thoroughly inspect every vehicle.

Congress has authorized $1.5 billion in recent years to upgrade security at border checkpoints, but Lou Barletta, the Republican chairman of the House Subcommittee on Border and Maritime Security, said at a hearing last year that the border crossings “have not kept up with the new technologies, threats, and traffic.” If stopping smuggling is among the priorities, the billions that could go toward building a wall would be better spent on more manpower at the busiest points of entry from the U.S. to Mexico.

For people like Taylor, the woman who is stuck south of the wall in Texas, the frustration over the GOP’s fixation on the border fence is palpable. “To throw more money at it when we need it for education and so many other things, it would be ridiculous,” she said.

Taylor is no fan of Hillary Clinton and she doesn’t support allowing undocumented immigrants into the country, but she’s certain that a wall isn’t the solution to smuggling.

“Trump is talking about building a bigger wall,” Taylor said. “Then we’re going to have bigger ladders.”