I totally understand what you mean. I took a group to the Twins game last week, had free tickets. I don't care who wins and I get evil eyed when any team makes a good play because I cheer and clap. I like good baseball, I have no allegiance to any team. I'm not a good tribal member, I'd rather not pledge allegiance to a flag, I don't think America is the Best country in the world. I don't drink the Best coffee or work at the Best school, or live in the Best neighborhood. I do feel like an outsider a lot because of my lack of need to fit in and be concerned about being the best at anything. If I like it I'll do it even if I suck at it. No team or tribe would have me, touche!

I live in the Bible Belt. Maybe it's just me, but it seems like here especially the masses are being influenced (dare I say, almost controlled) via highly emotional things such as religion, sports (especially football), school rivalries, patriotism/nationalism/immigration, military/guns/authority, etc. Groupthink scares me sometimes...

It’s not like religion at all. It’s tribalism. We are a herd animal, tribes if you like, but unlike other animals we each belong to many tribes. Our work tribe, our family tribe, our friends’ tribe, our football team’s tribes, etc. You could go on and on.

Within each tribe, we have our own personal loyalties and conflicts, but there is an underlying loyalty to the tribe itself. When one of our tribes is in conflict with another (say, a football game), the more ‘excitable’ members of each tribe of supporters can come to blows, or at least mutual abuse.

The complicating factor in all of this is that often there is overlap between one tribe and another, in terms of the people we individually know and love. Our immediate family tribe could have members who belong to different football tribes. At times like this, we normally subdue our loyalty to one tribe in favour of the other, depending on which tribe we’re in at the time.

Nothing’s simple, is it? ?

To a degree. Those of us with any sense realize it's just a sport, and particularly in professional sports, the players come from all over the country and are not by any means "home grown" or local. The rest who go over the top with the rivalries are Trump voters; you will always have that type around.

I would argue that at least sports teams are real and tangible. Not condoning violence over wins or losses in any way. I am a huge football fan, and have never once been involved in a violent act over my team. Although my team hardly ever loses

Sports fandom is an outlet for any kind of tribalism/us vs them impulse.

No. Outside of a common need that people have to classify themselves to find their place in the social order. Which groups are "my people" and which groups are "those" people? That happens with literally any term you would use to identify a person as you mentioned a few. What you described is common among all groups not specific to religion and sports fandom.