CNN used to have a debating show called Crossfire. It featured a liberal guest vs. a conservative guest, aided by a liberal and a conservative debater. The professional debaters (who were the show's stars) would help the guests when the guests reacted too slow or were too harassed to reply.
As to rationality: a debate is allegedly a 'rational' discussion but the most important thing, as in politics, is emotion, not rationality. The winner is the one who can convince the audience that he is right and the other isn't because they believe Him rather than his arguments. Rational arguments are only used to hide the debater's manipulation of the audience's emotions.
Example:
On Crossfire a few years ago I watched a discussion between a democrat and a conservative (sorry republican). The issue was that the democrat wanted an enquiery into some business, but the republican was against. Because it would cost (hand gestures) millions and millions. He repeated this about two or three times (hand and facial gestures included) so he was really playing to the tv-audience, who would most likeley remember: "Hey, that is OUR tax-money. Millions and millions."
At one time the republican even questioned the integrity of the democrat (always a nice debating-tactic but risky) by asking him how much he would get for his book (the democrat had written a book on the topic; that was why he was on the show).
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