Just because that is known and common, it surprises me that American political camps, even those who boast they're the good ones in the game, don't recognize it on themselves that they're moving into such kind of direction of producing monoculture and dogmatism.
Saying, to me it sometimes appears like there is something in the water that makes certain areas whole strongholds of one direction of thought.
(Technically I know that much about extremism and monoculture that they can pretty much create this die-hard and snobby atmosphere themselves by just radicalizing their members themselves. "We against them"-thinking coupled with "we've found the only one and true path".)

The power question - when taking a look at concrete political organizations that habor certain mindsets, then it seems obviously, when anything comes from these organizations, that they just want control. Regardless of if their positions are factually right or wrong. It's just a battle for the sunny places at the beach, you can say.
But when single people speak similar opinions, just because they allocate themselves to a certain political direction, then, at first, I'm missing this center of power in the game. (And where I can locate this entity who seeks power that has infected the thought of these single people, all of that is much unproven conspiracy theory, which you don't know about if it's true or not.)
Literally: What do these people gain personally when they make me believe in the same stuff that they do?
Only I can think of "the feeling of being on the right track". Erasing doubt, erasing everything that can destroy your little dreamworld and, by that, take away the ground beneath your feet. Take away the insecurity, when everything they believe in should turn out to be wrong.

But when it's about that, there must be a pretty high degree of personal insecurity in the game...