This separation leads increasingly to enmity

From “The Seven Democratic Virtues: What You Can Do to Overcome Tribalism and Save Our Democracy” by Christopher Beem

Aligned tribes are also separate tribes. As each tribe reinforces an overriding sense of us, it also leads to less interaction with them. Aligned partisans are even less likely to have friends or even contact with the other side. Their family and friends are likely of the same tribe, consume the same media, and frequent the same places. As a result, alignment leads to more extreme positions and a more unshakeable commitment to them – and to increased ignorance, distrust, and negative stereotyping about the other side. Both Democrats and Republicans know that they see the world differently, that they like different things and go to different places. But this sense extends beyond culture to a basic understanding of what it means to be an American. Both sides increasingly believe that the other party cannot be trusted, that their very goals undermine the well-being of the nation. Ultimately, as I have noted, this separation leads increasingly to enmity and even an openness to violence.