Dehumanization is not a Malfunction of our Politics

The more diverse America gets, the less we have in common with our fellow citizens, the less likely we are to see each other as human.
Even the biggest brains have limited capacity for empathy. Evolution designed us to use our emotions and morals to navigate within our tribe. The only evolutionary reason to do it for those in out-groups is get resources for your tribe.
We evolved in small groups where the in-group versus out-group split was the basic survival calculation. Cooperation inside, suspicion or hostility outside. Mearsheimer has it right that we are social before we are individual, and the liberal pretense otherwise is a recent ideological overlay on a much older substrate. Pinsof’s Alliance Theory makes the same point at the individual level. Beliefs function as coalition signals, and coalition membership is the mammal’s primary survival strategy.
Once you accept that, dehumanization is not a malfunction but a feature. When two coalitions compete for control of the coercive apparatus, each must motivate its members to pay the costs of fighting. Treating opponents as fully rational agents with legitimate interests dampens that motivation. Treating them as evil, stupid, or subhuman raises it. The wartime caricature of the enemy is not a regrettable excess. It is what allows ordinary men to kill, vote against their neighbors’ interests, or cheer policies that crush other men’s lives.
The preaching against dehumanization is usually a coalition move. Notice who does the preaching and against whom. The sermon almost always points one direction. The coalition issuing it gets to define which dehumanizations count and which do not. Calling your opponents fascists, bigots, deplorables, knuckle-draggers, or enemies of democracy somehow does not register, while milder language directed the other way registers as a crisis. The sermon is a weapon dressed as a rebuke of weapons.
Diversity intensifies all of this. Putnam’s data on social trust collapsing in diverse communities, the cross-national work on ethnic fractionalization and public goods provision, the historical record of multiethnic empires holding together only through hard imperial machinery. The pattern holds. Men extend trust and forbearance most easily to those they recognize as their own. As the in-group shrinks and the field of strangers grows, the cost of restraint rises and the temptation to dehumanize rises with it. The preaching gets louder because the pressure is greater, not because the preachers have grown more virtuous.
Two qualifications.
First, the intensity of dehumanization varies, and the variation matters for how many men get killed or imprisoned. Institutions, norms, and rituals do not abolish tribalism. They channel it. A society that lets coalitions fight through elections, courts, and journalism sheds less blood than one that lets them fight through militias. The talk about not dehumanizing your opponents is often dishonest, but the underlying norm of restraint, where it holds, is part of why America is not Rwanda in 1994.
Second, the cynical move (politics is war, drop the pretense) is a coalition position. It plays well in some coalitions and poorly in others. Saying it out loud is a status move within a coalition that prides itself on seeing through liberal pieties. The man who says “let us be honest, this is just power” is not standing outside the game. He is signaling membership in a particular faction inside it.
Dehumanization is a near-constant pressure. The preaching against it is mostly weaponized. Diversity raises the temperature. And the men who notice all this are still inside the same evolved apparatus they describe. The sermon is a tactic. So is the anti-sermon.