A common enemy is an important element of group dynamics, so yes Democrats need an enemy even if they must invent one.
Right, but the normal impulse is to use some “outsider” as the common enemy. So the English point across the channel at the French and the French point back at the English. That’s the “non-pathological”, or maybe “less pathological” way that societies satisfy that need.
The leftist, however, always looks for an internal enemy instead. They point the finger at their neighbors, never at the stranger or the foreigner. This way, they turn a tactic that is supposed to foster unity among society into one that sows dissension and instability. It’s a pathological twisting of this universal tendency.