Maria Corina Machado: Can Venezuela's fortunes change?

Sarah Montague speaks to Venezuelan opposition politician Maria Corina Machado. Banned from running in the country’s presidential elections this weekend, she’s still a leading figure in the movement trying to unseat socialist authoritarian Nicolas Maduro. With the country’s economy in ruins and more than a quarter of the population having fled, could the next few days change the fortunes of this oil-rich but very troubled nation?