"Unlike his primary debates that included multiple candidates, Mr. Trump will have much more time to respond to questions. He can't fill his entire talk time with his signature glib one-liners or with self-praise the entire evening. He needs to demonstrate to voters that he has sufficient substance to be commander in chief," Mr. McKinney tells The Beltway.
"When we've polled debate viewers, the candidate that is seen as spouting the most facts and figures and technical policy language is seen as the loser of the debate," said Mitchell McKinney, director of the Political Communication Institute at the University of Missouri. "If one takes their task as trying to prove to the American people that they are smarter than their opponent, that they know more, that doesn't play well on the debate stage."