What does a multibillion-dollar mistake look like? He looks like a 70-year-old demagogue politician who occupies the White House. And it appears we will have a big-ass wall to remind us of it.

If President Donald Trump follows through with his promise to build a ridiculous wall under the pretext of stopping migrants and drugs from entering the U.S., we will have a constant reminder when our tax dollars build his wall.

Regarding immigration I’m no expert on that matter. That said, according to the Pew Research Center in a five-year period from 2009 through 2014, there was a significant decrease in the number of Mexican migrants residing in the U.S. This is relevant as Trump continues to unilaterally destroy bilateral relations with Mexico at levels not seen probably since the Mexican-American war.

According to the 2014 Mexican National Survey of Demographic Dynamics, between the same period of 2009-2014, roughly one million Mexican nationals and their families, including their American-born children, left the U.S. for Mexico. These trends continue today, and according to the William C. VelÃ¡squez Institute, “the southern border with Mexico has experienced near zero or zero net migration since 2007, thus there is no rational basis for a border wall.”

Yes there’s activity on the border, but to argue that immigration to the U.S. is out of control only to support his political position is simply wrong and akin to the propaganda promoted by the GDR when building the Antifaschistischer Schutzwall, aka the Berlin Wall.

With regard to the idea that building a wall to stop the flow of drugs, well that’s perhaps twice as naÃ¯ve, if not outright stupid. Notwithstanding the role of the American appetite for drugs, the existing walls along the border have done absolutely nothing to stop the flow of drugs, other than to motivate more creative methods of transport.

Since 2006 more than 80 underground tunnels have been discovered. The tunnels have become so popular that homeland security and other local law enforcement are working together in a special task force called the San Diego Tunnel Task Force.

These sophisticated tunnels cost an average $1 million and usually the very first load pays the costs associated, which include among others lighting systems, air ventilation, pulley carts on tracks, and water pumping equipment with generators for some of the buildings. One recent tunnel discovered last April was nearly 800 meters long—the length of more than 8 ½ football fields.

There are many other more creative methods of successfully smuggling goods. Those include an improvised mobile PVC pipe truck-mounted cannon that shoots bundles of drugs over the wall, a smaller hand-held version of which is a modified t-shirt shooter like those found at sporting events.

If that’s not simple enough for you then we have one of my favorites—the catapult. We also have the ultra-light remote control drones—some of which can carry up to 300 lbs of goods.

There also are ramps designed to drive over the walls and submersibles, which continue to grow in popularity. So building a “fortified” wall is as stupid a solution as is walking around with a cardboard umbrella in a thunderstorm.

So what’s the solution? Legalization. Yes, legalize marijuana, which is the number one producer of wealth for the cartels. End the federal prohibition, reschedule cannabis, invest in research and infrastructure, support medical advances and improve upon the nation’s economy all the while ending the war on drugs and dismantling the illicit market, which thrives on prohibition.

In places like Colorado and other legalized states, we are already see a decrease on cartel activity and soon California will follow. With nothing more than responsible legislation and a signature drug law reform can help dismantle the drug trade and be infinitely more effective than any wall ever has been or will be.