 Situation of a former president running against a current president and this election is sort of teetering on a knife's edge. Sarah DePerry, a former Obama speechwriter, says this debate could also make or break each candidate's run for the White House. The questions that voters have about both of these candidates can in some ways be answered by the debate and how they perform. That means voters will be paying attention to the substance of the debate, but also to the tone.