The bumper stickers we plaster on our cars are tribal insignia. Have you ever seen a bumper sticker promoting a political candidate whom you abhor and felt a reasonless rage build up inside of you? I have. I feel an instinctive rush of enmity toward those people while knowing that they probably are decent humans in spite of their obvious ignorance. We all need to belong somewhere. Our churches are one kind of tribal affiliation. For some fundamentalist groups, it is the only tribe they claim. Any other group membership would be treason for them. For teenagers, it may be the goth look that they cultivate, in order to proclaim their membership in the disaffected youth tribe. Tribalism was adaptive for early humans. It became maladaptive when some groups learned to work together to achieve common goals. A focused united nation can almost always overcome a cluster of tribes if they really try. Think of the Roman empire, the Norman conquest, or the Spanish conquest of Latin America. The danger in the US now is that some people ( you know who you are) are stirring up tribal passions, destroying us as a united people. They are creating scapegoats on whom to place all the blame for everything wrong in the world today. They are doing this in order to grab the reins of power, certainly. Homosexuals are not such great scapegoats any more because too many of us cherish the gay members of our family and friends. They belong to our tribe. But persons of a different color still work as scapegoats in the minds of the ones who play the game of divide and conquer. It's not so acceptable to use African-Americans as scapegoats now, but it seems to be just dandy to use Latin appearing people. Or people who are Muslim.
It's too bad. I hate to see our once great melting pot country turned into a petty tribal conglomerate of warring groups.