not sure why anyone would bother with the debate besides for comedy reason and the "social commentary" they're both just going to sprout off utter garbage and try to throw zingers at each other while doing absolutely nothing useful.
It's like kids who got caught misbehaving by their parents and start grassing each other up to make themselves look better. Trump will bring up emails, Hiliary will bring up tax returns, repeat in various forms. The whole thing is basically them shouting out "BUT YOU'RE WORSE"