Marianela Rojas huddles in prayer with fellow migrants after trudging across a slow-flowing stretch of the Rio Grande and nearly collapsing when she stepped on American soil for the first time.

“I won’t say it again,” interrupts a U.S. Border Patrol agent, giving orders in Spanish for Rojas and a group of 14 other Venezuelans to get into a detention van. “Only passports and money in your hands. Everything else — earrings, chains, rings, watches — in your backpacks.”

It’s a frequent scene across the U.S.-Mexico border at a time of swelling migration. But these aren’t farmers and low-wage workers from Mexico or Central America, who make up the bulk of those crossing. Among them are bankers, doctors and engineers from Venezuela, and they’re arriving in record numbers as they flee turmoil in the country with the world’s largest oil reserves and pandemic-induced pain across South America.