Taunting opponents in order to drive them into an impulsive emotional reaction, and damaging their own reputation by their own hands.
Damaging the opponents' reputation is one of the main tactics of mainstream propaganda, but if the opponent is an honest person, this is difficult to do directly, so they try to push them to blackwash themself by their own hands. Creating an hostile environment around the opponent (through arrogance, derision, threats, etc.) is useful to make him feel surrounded making him lose his patience and objectivety; also, it creates a personal resentment which is very dangerous because it changes his focus from *exposing the truth* to *gaining victory*, strongly increasing his aggressivity and his chances of fatal mistakes.
The trick for the best results, however, is to taunt the opponent without ever assuming an explicitly hostile behavior, but let him be the one to start the fight first: this way he'll automatically be seen as the only one at fault; this can be achieved in various ways, like personal insinuations, veiled insults, passive-aggressive attitude, openly dishonest arguments made in a polite manner, etc.