President George HW Bush checked his watch during a question from a voter in 1992. Al Gore got awkwardly close to George W. Bush in 2000.

Town hall debates tend to put a spotlight on a candidate's style, as much as their substance. And this, say some analysts and couch pundits, is the challenge for Hillary Clinton and Donald Trump for this Sunday night's debate.

They will be fielding questions from undecided voters at Washington University in St. Louis.

MORE: Campaign 2016 U

Who will do better in a town hall-style debate? This is the question posed today to a group of American University students WUSA*9 has been following every week for what we call: Campaign 2016 U.

Who won the Vice Presidential Debate?

Performance vs. Truth