President Trump vowed throughout his campaign to build a “beautiful” wall along the 2,000-plus-mile US-Mexican border — and to make Mexico pay for it. Mexico is saying no way.

But the US-Mexican border already has a wall and critics question its usefulness. So what exactly is the point of the second wall, would it work and who stands to benefit most?

In this interview on KCRW interview, Michael Dear explains why a second wall along the U.S. Mexico border appeals to few except perhaps drug cartels and the border industrial complex.

“When we talk about walls everyone always says don’t forget about ‘outa’. People always find their way over, under, through, or around walls. You can’t stop it.”

Listen to the full interview here.