Debate is best not substitute taught. When it must be substitute taught, it is best not done by the young.
At least once a year, I have a sub in Debate (usually a college kid) who grows bored with the plans I leave and tells my class, "Let's just debate!". It goes awry. It goes terribly, terribly awry and the next day I have riled up children. One year a kid even came to me in tears--the next day.
We always debrief the next day. It's a good time for me to teach the reasons we have structured argument. Structure ideally allows for the voice of the minority. Ideally, it allows the best idea to win and not the loudest. I always wonder aloud what would happen if our courts were run the way my classroom was on those horrid days and someone always says, "We would all go to jail.".
So today, I am preparing them for a sub and I describe the horror of unordered debate. They are right there with me and ask "What do we do if the sub tries to make us debate like that?". I think a moment. "Go limp. Do not engage, do not make eye contact. Refuse to play their game."
Right then, standing at my podium, I watch 27 bodies go totally limp at the exact same second.
and I remembered again why I teach.