How we change what others think, feel, believe and do
Call them names
Laugh at what targeted others say. Criticize their lack of Values. Denounce their ideals. Turn around their words and actions, taking them out of context and amplifying them to drown out any denial (making denial seem like admission of guilt). Use other double-binds such that whatever they say or do only mires them more deeply.
Find a name that trivializes them and use it at every opportunity, with a smirk on your face and the laughter of your supporters.
Show up opponents
Make your opponents appear stupid, immoral or otherwise undesirable. Besmirch their untarnished reputation, holding it down in the mud, rubbing it in with the knowledge that much of the mud will stick. Be careful about the person retaliating. As necessary, ensure they are isolated and disempowered first.
Make an example of someone
Take a random person and denigrate them. Show that you can and will do this any opponents.
You can do it to an apparently strong person, to demonstrate that you are not afraid and will take on and defeat even the powerful. You can do it to a weak person, to show that nobody is safe from your ire. You can do it to an ordinary, guy-next-door person, to show that 'people like you' are not safe either.
My opponent is a flip-flop man who cannot make up his mind. He changes mind with the breeze! How could anyone follow such a weak-willed flip-flopper?
Mud sticks, as we all known. Name-calling associates the other person with something that is despised or is inferior in some way. Now, if anyone associates with that person, the mud will also stick to them. The more the other person is socially isolated, the more that others will avoid the person. The results is a spiral of isolation that neutralizes opponents and sends a chilling warning to those who might follow in that person's path.
Note how, especially in wartime, the other side gets given a whole slew of derogatory names. In the second world war, the Germans were called Huns, Krauts, the Boche, etc. The Japanese were called Nips, Japs, Slant-eyes, and so on.
Name-calling happens also in activism. Calling the police 'pigs', for example, is not just a derogatory term, it also frames the whole structure of state authority as dirty and unprincipled, hence making them unworthy and legitimizing attacks on them.
Note also political elections, and how easily debates can descend into name-calling from which there is no recovery.
Clyde Miller, Propaganda Analysis, NY: Institute for Propaganda Analysis, 1937