Heilyn Rojas, a 21-year-old Venezuelan student, left her country last year, tired of the crime and food shortages back home. She fled to neighboring Colombia in search of a better life.

Now, on the eve of Pope Francis’ five-day visit to Colombia, she stands among many Venezuelans, including bishops and opposition leaders, who hope the pontiff will chastise Venezuelan President Nicolás Maduro for his role in the nation’s economic collapse and its deep political strife.

...