CARACAS, Venezuela—The people in this city’s largest slum had plenty of reasons to reject Venezuelan President Nicolás Maduro in Sunday’s election: hyperinflation, a collapse in public services, shortages of medicines.

But Angie Chong, a pro-government activist, embodied for Petare residents of one very big reason to cast their ballot for Mr. Maduro: hunger. She and a team of “patrollers”—many of them the same people who distribute boxes and bags of state food aid in the slum each month—went door-to-door after dawn, rousing...