Donald Trump's border-wall proposal has been roundly excoriated, and experts have told Business Insider that the wall itself would not only be impractical, but it may also embolden the very criminals it's supposed to stop.
"Donald Trump talks tough about the cartels, but his policies are tailor-made to increase their profits," Tom Wainwright, author of "Narconomics" and previously The Economist's reporter in Mexico City, told Business Insider.
"He talks a crackdown at the border, but crossing the border is what they do best, it's where their advantage lies, that's where they make their money, that's why drugs cost so much more in the States than they do in Mexico."
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Americans spent more than $100 billion on illegal drugs in 2010, according to a White House study, and many of those drugs get a substantial markup because of the difficulty involved in getting them to the consumer.
A border wall may raise the prices of drugs, but it "won't do much to reduce consumption, because people who are addicted to drugs on the whole are very responsive to prices," Wainwright said. "So all it will succeed in doing is inflating the value of the criminal economy."
In the case of cocaine, the price goes from a few hundred dollars for the coca leaves needed to make it in Colombia, to "more like $150,000 per kilo," when it retails on US streets, Wainwright told Business Insider in an interview, a price that would likely rise with a border wall.
"I think if the cartels could vote, they would vote for Donald Trump. His policies suit them down to the ground," Wainwright added.
'Punch a hole through it'
"Trump's wall would not have any impact on the movement of drugs through the US-Mexico border," Mike Vigil, a retired DEA agent who spent time undercover in Mexico and Colombia, told Business Insider.
"The Mexican drug traffickers would punch a hole through it, fly over it," Vigil added. "They would be able to circumvent that with medieval technology, catapults, shooting stuff across the wall."
Suggesting drug traffickers could fly or fling drugs over a border wall is not speculation. They have done just that.
In the past, cartels have made use of fleets of hundreds of aircraft to move shipments of drugs over the border clandestinely. More recently, traffickers have employed ultralight crafts and drones to ferry drugs into the US.
In another, more low-tech effort, smugglers used a catapult to hurl marijuana over the Arizona border.
"They just put the drugs there and whoom! — over the border fence, and then somebody picks it up on the other side," journalist Ioan Grillo told Business Insider.
Mexican cartels have also proved adept at transporting illegal drugs by sea, in both ships and on homemade narco submarines. The occasional bust of seaborne narcotics may be a sign of how lucrative this method is.
"Donald Trump is mentioning this wall like it's going to have an impact because he's playing to what people want to believe that he's going to do in terms of immigration," said Vigil. "But that wall would serve absolutely no purpose."
'The only way ... to stop it is with boots on the ground'
The benefits of a wall — which Trump's varying estimates put at anywhere from 30 feet to 65 feet tall — closing off the US-Mexico border have also been called into question by people who live along the frontier.
Ranchers and other residents near the border in southwest New Mexico have seen an uptick in incidents related to illegal border crossings, including break-ins and, late last year, a brief kidnapping, according to the Albuquerque Journal.
"The vandalism and the trespass issues have increased," Erica Valdez, who ranches more than 40,000 acres in Hidalgo county, New Mexico, which makes up the state's bootheel, told the Journal in early March.
But, despite these criminal incursions, residents seem wary of Donald Trump's promises "to close up that border and ... build a wall."
"The border is not secure ... It doesn't matter how tall of a wall you put up, they are going to tunnel under it, they are going to torch through it. If they want to come across, they will," Valdez said, in what seems to be a reference to Trump's proposed border wall.
Despite the Border Patrol intercepting 11,000 unauthorized border-crossers in fiscal year 2015, "The folks down there have never gotten any relief from illegal crossings," Caren Cowan, executive director of the New Mexico Cattle Growers' Association, told the Journal.
Rather than a static wall, residents in the area have pushed for a larger Border Patrol presence, which the agency has said it is in the process of deploying.
"The only way they are going to stop it is with boots on the ground at the border," Valdez said. "We would like to see more agents."