María Corina Machado: Defending democracy in Venezuela

Stephen Sackur speaks to the de-facto leader of the Venezuelan opposition, María Corina Machado. Two months after an election which she says delivered a humiliating defeat to the country's authoritarian leader President Nicolás Maduro, he’s clinging on to power and his regime is clamping down on dissent. Have hopes for change again been thwarted in Venezuela?