The people on the Mexico side of Trump's wall say it'll never work

President Trump visited California last week for the first time since he took office, to inspect prototypes for his promised U.S.-Mexico border wall -- a barrier against “hellish violence,” he called it.

“If we don’t have a wall system, we’re not going to have a country,” Trump said in a recent Twitter post, where he included this promotional video for the wall.

But that message is heard not only by the people Trump claims to be protecting but also by those he's trying to keep out.

Just a few yards away, on the Mexican side of the border, residents living in the shadows of the existing fence have their own views about the likely effects of Trump’s wall. And the common theme from their views is this: No wall, big or small, will stop those who want to get into the United States.

Related: Trump's wall could cause the extinction of the American jaguar

This segment originally aired March 13, 2018, on VICE News Tonight on HBO.

Gaby Córdova and Nate Anderson contributed to this report.