I believe that Naomi Wolfe and his daughter Karena were his handlers at the time, and they could have told him to do anything. As I recall, they were working on boosting his "alpha"index. That's probably what that bone-head move was all about.
However, Lehrer as moderator looked even worse than Gore. I honestly don't know why he was even there. He refused to hold Gore to the rules of debate.
I remember that. Some news articles at the time were referring to Bush's deflection of Gore's intimidating posture as "The Nod. Bush looked human and in control--and Gore appeared like a bully who was really wetting his pants while trying to appear in control.
Shortly after that--I read that Gore wanted to "Out Alpha Male" Bush again--but Gore's handlers were dead set against it. Gore wanted to bring up his "service" in Vietnam and contrast that to Bush's--something about "Trodding through the elephant grass while Charlie had us in their sights...the sweat breaking on my brow as I scanned for V.C........"
Gore's people were afraid that if he brought up his military record, too much light would be shone on Prince Albert favorable treatment by his Senator Father--and his posting in the rear in a ridiculous job as a journalist. Gore's reflections of his short time in Vietnam were complete fiction--and only Gore believed his own gyrations of the truth.-- most of all his failure to serve a complete tour! This is what struck his staff with fear the most: Gore spent only a few weeks in Vietnam--and came home waaaay early after writing a few puff pieces from the rear. It was delicious to read at the time how Gore was chomping at the bit to talk about his "war record"--and his campaign handlers were aghast.