A debate should involve the expression and comparison of ideas.
One side should challenge the other when necessary, and the ideal outcome is that all involved parties are able to say their piece, distinguish their arguments from those of their opponent, and walk away knowing that information was distributed. Everyone learned something, even if they don’t agree with everything said.
When is the last time you walked away from a political debate feeling enlightened? In most cases, such ‘debates’ are no more than parallel speech-fights, where one combatant has their say while the other nods their head condescendingly before launching into their own monologue. The speeches presented generally somehow relate to the question asked, but rarely answer them with specifics, and sometimes veer so far off that they end up answering questions that weren’t asked to begin with.
Of course, politics isn’t alone in hosting such debates. Most formalized arguments over ideological topics end up the same way, with both sides talking past the other, decisions already made. Who has ever been shouted at by a political, technological, or religious diehard and had their mind changed as a result?
This isn’t to say that it’s impossible to have a productive debate — they do happen from time to time, though rarely in public, and rarely between people who are elected into their jobs — but it is incredibly difficult, and generally only possible if everyone involved enters with the intent of learning as well as teaching.
Imagine entering into an ideological discussion not knowing what you’ll believe when it’s over, knowing the other people involved can be convinced, as well.
The concept is almost beyond comprehension in some settings — a purposeful debate! — but it’s nice to think we all might be open to learning and adjusting based on new information rather than holding to party, faith-based, or other ideological lines, too stubborn to listen to what other minds — with other ideas and other perspectives from which to view problems — have to say.