Let's say that someone wanted to preserve as much fear and hostility as possible in their own public with regards to another party. In that case they would not want to have any public dialogue with that other party. They would want to stifle all possibility of such dialogue...in case the dialogue might lead in some positive direction.

This is why dictators and demagogues the world over don't want an open public dialogue with any of their chosen enemies. It might interfere with their promoting and maintaining a state of fear and crisis at home.

"If you stifle his oratory, you have nothing valid to argue or agree with."

Correct. Of course if someone wants nothing valid to argue or agree with...but just wants an official "bad guy" for people to vent hatred upon...then the obvious solution is: stifle his oratory, refuse to engage in dialogue with him or his underlings, when you report what he says only repeat a fragment of it preferably out of context, whatever fragment can be made to look most evil.

And that, my friends, is standard propaganda technique just about everywhere. The Bush administration does it. I bet Ahmadinejad does it too, back in Iran.

The rule is...repeat nothing the official "bad guy" says, unless it is something that can be made to look evil, sneaky, or duplicitous.

Hmmm. Kind of sounds like what happens on this forum with people who attack and nitpick the statements of their political opponents, doesn't it? ;-) From the halls of power to the peanut gallery, the tactics of ill will are much the same.