An immoral debate depends on the definition of a corrupt debate. A corrupt debate is where:
1) debaters willfully produce responses that contain bad arguments or logical fallacies
2) debaters willfully conduct arguments toward an audience without knowledge of logical fallacies and/or without knowledge of critical thinking
3) debaters willfully conduct arguments in a venue or theater where non-logical aspects of communication could manipulate the behavior of others, and leverage those aspects in the delivery of their arguments.
A corrupt debate is an immoral debate if performed where the debate is part of a process affecting a large number of people who consider themselves a society, because:
1) while those debating look like they are arguing and analyzing an issue, and trying to come to a logically correct conclusion, they are really manipulating an audience to effect a desired outcome,
2) if debate is the foundation of determining the direction of a society, corrupt debate skews it towards the will of specific individuals rather than objective truth.