Most of the people moving drugs from Mexico to the U.S. are not Mexicans, an expert says. 

“Most drug smugglers are U.S. citizens,” Maureen Franco, chief federal public defender in the Western District of Texas told United Press International

If that's true, and the data isn't clear either way, then it knocks a hole in President Trump's argument for a border wall. 

The UPI also reported that, at the New York trial of Mexican drug trafficker Joaquin “El Chapo” Guzman, a key witness testified that the Sinaloa Cartel specifically recruited U.S. citizens in El Paso to smuggle drugs across the border at ports of entry.

In conversations with American residents of El Paso, an American town on the border with Mexico, this reporter learned that it was common for college students looking for a quick buck to smuggle drugs across the borer, either up their asses or inside their cars.  

That makes them especially hard to stop, since they have the right to cross the border and come to this side. The border patrol isn't able to check every American citizen's car. Or cavities. 

The federal government has been shut down for nearly a month as President Trump demands Democrats in congress allocate $5 billion for steel slats along the border. As of now, only about 580 miles of the 2,000 mile border is secured with a wall or fence. The rest is protected by the Rio Grande River or by deserts or canyons that are difficult to trek across.  Trump has said one of the reasons for the wall is to stop damaging drugs like opioids and meth. 

Yes, some drugs come to the U.S. through gaps in the wall. They're called "backpackers," and they trudge through the desert or swim across the Rio Grande River. 

But a much greater tonnage of drugs travels through the checkpoints, in car bumpers and mixed in with legitimate merchandise like fruit or electronics or clothes. 

A wall won't make any difference on any of that, most experts agree. 

Luis Chaparro, a reporter who covers the cartels, told Rooster that Trump's wall is ridiculous, in terms of stopping drugs. 

"No one's even using the tunnels right now. Everyone's just crossing on the bridge" for cars on, Chaparro said. The smugglers are either U.S. citizens or they use fake papers that say they are, Chaparro said. A wall, Chaparro said, "is not going to stop anything."