You might want to go back in time to September 26, 1960, when 70 million viewers watched the first presidential debate between Senator John F. Kennedy and Vice President Richard Nixon. This was the first presidential debate ever televised, and after this debate Kennedy moved from a slight deficit into a slight lead over Nixon.
There's some interesting commentary before the debate about how Nixon didn't prepare his image very well before the debate and how he frequently appeared shifty eyed (always looking at the clock). Kennedy prepared extensively beforehand and appeared rested, confident, and relaxed. Besides the image politics involved in the debate, it's also interesting to hear the major issues from 1960, and how drastically they differ from the issues of today. This debate is available on streaming video from PBS through YouTube.