By Amy Isackson
The World programme, San Diego
Declarations of emergency in US border states like Arizona and New Mexico have kicked the immigration debate into high gear.
Judi Werthein is handing out free "crossing trainers" to migrants
Artist Judi Werthein has walked smack into the middle of this controversy.
She is hoping to leave her footprint with a special "crossing trainer" she has designed to help illegal immigrants negotiate the sometimes deadly terrain they encounter when crossing the border from Mexico to the US.
Migrants waiting for dark to hop the border fence from Tijuana into San Diego start calling out their shoe sizes when they see the boxes in Werthein's arms.
People start emerging from their makeshift homes in rusted cars and the cement channel that runs parallel to the border fence and drains Tijuana's fetid run-off.
Some have been waiting for months in this no-man's land for their chance to cross into San Diego.
They call the act of crossing the "brinco" - literally "jump" in Spanish. And that is the inspiration for Werthein's crossing shoes, called Brincos.
The trainers are adorned with unusual items.
"The shoe includes a compass, a flashlight because people cross at night, and inside is included also some Tylenol painkillers because many people get injured during crossing," Werthein says.
The trainers are equipped with a compass, light, map and painkillers
The artist was commissioned by a cross-border arts exhibition called inSite to develop a project that "intervened" in some aspect of border life.
While researching her project, the Argentine native became fascinated by illegal immigrants' primary mode of transportation - their feet.
"If they go through the sierra, they walk eight hours. Their feet get hurt. There's a lot of stones and there are snakes, tarantulas. So that's why it is a little boot," she says.
The Brinco is an ankle-high trainer which is green, red, black and yellow.
An Aztec eagle is embroidered on the heel. On the toe is the American eagle found on the US quarter, to represent the American dream the migrants are chasing.
A map - printed on the shoe's removable insole - shows the most popular illegal routes from Tijuana into San Diego.
First new shoes
Guadalupe Elias has arrived at the Madre Asunta migrant shelter in Tijuana. Catholic nuns run the refuge for women and children making their way north.
After the 48-hour trip from her home in southern Mexico, Ms Elias' trainers are ruined.
She tells Werthein, who has come to the shelter to pass out Brincos, that she needs shoes that fit.
Werthein gives her a pair of Brincos - and Ms Elias begins to cry.
"I'm crying because you gave me these and almost no-one ever helps me," she explains, adding that she has never owned new shoes before.
A few days after passing out shoes for free to migrants, Werthein begins selling the shoes at a hip boutique trainer store in downtown San Diego.
The shop sells only limited edition trainers. A pair of Werthein's Brincos are displayed on a pedestal under glass with a price tag of $215 (£125).
Though the store is only about 15 miles (24km) from Tijuana, here the champagne-sipping crowd sees the Brinco as a vehicle for discussion - not transport.
Andrea Schmidt, of La Jolla, is buying a pair to display in her living room.
"I think they're historical. I think it depicts a very special problem. And I thought it was important to have them," she says.
But her husband, Joe, thinks her purchase crosses a line.
He says: "It does give them an incentive to come. Because these are probably the best shoes they've ever had in their lives."
Werthein dismisses complaints that she is aiding and abetting illegal immigrants.
She argues she is just provoking an important discussion. The real incentive for illegal immigrants, she says, is Americans' demand for cheap labour.