Political debate: the dos and don'ts

When presidential candidates walk away from their debate podiums, how does anyone know who won and who lost? What are the tricks and tips of being a winning debater? Andrew Markoff - a champion debater, Associate Director of Debate at Georgetown University and co-founder of Speech Labs - answers these questions and more in 'the dos and don'ts' of debates. (Natalie Fertig / McClatchy)