Your task is to define yourself as the friend of as large a constituency compatible with your principles as possible, while defining your opponent as their enemy wherever and whenever you can. The act of defining combatants is analogous to the military concept of choosing the terrain of battle. But be careful. If you appear mean-spirited, nasty or too judgmental, it will make it easier for your opponent to define you as the enemy. In political warfare, the aggressor usually prevails .
Aggression is advantageous because politics is a war of position.
Position is defined by images that stick. By striking first, you can define the issues and define your adversary. This is the decisive move in all political warfare. Other things being equal, whoever is on the defensive is generally going to be on the losing side. Because going negative increases the risk of being defined as an enemy, it can be dangerous.