I know you didn’t address me, but what do you mean? What is?
I wish I knew. It is not groupthink. Although the facets of groupthink are held in common. It’s easily seen in sports at every level. For want of a better term I call it tribalism. The other tribe is your enemy on some level. It is not the spirit of competition. At its worse it’s beyond ugly. Hitler’s marginalization and eventual efforts to exterminate Jews is an extreme example.
Stirring up discontent with the rich vs. poor distraction is another practiced by politicians. They all have their roots in something very basic in human nature. Once someone has chosen a tribe, the committment is almost unshakeable. Neither common sense or logic applies at that point.
People who cling to a political party affiliation when common sense should convince one otherwise is another example.