Earlier this week, passengers boarded an airplane run by the low-cost carrier VivaAerobus in the Mexican beach resort of Huatulco. They hoped that soon they would arrive in Mexico City.They did not. Instead, their plane sat on the runway for around three hours, grounded after the Mexico City airport was closed by heavy rain. The passengers had to wait for a subsequent hour outside the plane before finally heading off.The delay would likely have been little noticed in Mexico had it not been for one passenger onboard. His name is Andres Manuel Lopez Obrador . . .