I would say one word covers a great deal of this (but certainly not all of it) - Tribalism.
People engaging politics in the same way as they engage sports, taking sides, living it almost entirelly at an emotional level, unquestioning of the superficial ideas (at times no more than slogans) they parrot and with thinking at best relegated to a supporting role as a "solver of puzzles" to come up with counter-"arguments" to those of the "other" side.
Whether one thinks oneself Left or Right (and, frankly, if you haven't tought through your politics in my opinion you're not really politically aware enough to be either), really analysing the pap one is fed by politicians in light of one's personal principles and of "how will this lead to the World I would like to live in" is usually quite the eye openner.