It all boils down to individuality: people don't have enough. They are too primitively tribal. That's right. They IDENTIFY as either Republican or Democrat, and this US vs THEM mentality is at the core of their being. Moreover, US citizens even DEFINE being a US citizen as being EITHER Democrat or Republican. Not all of them, but certainly enough of them.

Then you have the ego's psychology, which has a stake in being RIGHT, and in being part of the group that is right. Proving yourself right serves no actual purpose: it simply negates the objectiveness of actual reality, in favor of a subjective impression and feeling of power, of being 'right' even if the consequences of this being 'right' and the processes leading up to that and which follow that are all destructive.

In other words, the primitive, tribal part of the ego's psychology puts more value into being 'right' through voting for 'their' party and also WINNING than in the actual state of the nation or 'doing good'. Until that part is expunged and destroyed, this will keep happening. And TPTSNB know this full well, so they do their utmost to brainwash the masses into being tribal, primitive and self-righteous.

Eventually, they'll learn. Maybe only after the Earth is an actual wasteland, who knows.