Explainer: Will opposition leader Guaido topple Venezuela's President Maduro?

Venezuelan opposition leader Juan Guaido appeared alongside armed, uniformed men on Tuesday in his strongest call yet to the military to abandon President Nicolas Maduro, a day before planned mass protests aimed at toppling the socialist leader. In the more than three months since Guaido invoked the constitution to assume an interim presidency, citing fraudulent elections, Maduro has so far kept a grip on the levers of power including the military and security forces. Guaido says Maduro must step aside for a transitional government to organize new elections.