Covid pushed millions worldwide from the middle class to poverty. One man is trying to work his way back

CARTAGENA, Colombia - Marlon Mendoza, Certified Cartagena Tour Guide, stopped in the shade of a Spanish-colonial balcony and scanned the old slave market for prospects.

"#Localcartagenatours. Nobody Does It Better Than the Locals," the T-shirt on his back promised, although there were hardly any tourists left to look. Hundreds of miles away, American…