The red go-go boots are a half size too small, but I buy them anyway. It’s almost closing time at Mimi Shoes on South El Paso Street, just a few blocks from the Santa Fe bridge, which arcs south over the U.S.-Mexico border, carrying thousands of El Pasoans to and from Juárez every day. Surrounded by stacks of white shoeboxes brightened under fluorescent lights, the store’s owner, Ying, watches me, the only customer at this late hour, as I pace in front of the mirror. “This is the last pair,” she says, “and we won’t get new ones in until next fall.” My toes are squished, but I am three inches taller and feel like a superhero. I pay Ying thirty bucks and walk out into…