I remember my first boss who is now a higher up at >100 person company used to pick his nose just blatantly while talking to you. I had a number of interpretations of it lol.
I don't know really anything about LBJ but different people come from different backgrounds. My father was raised that it was not important to close the door while pooping and he didn't. It wasn't a power play. It was just normal to him. Both his parents did it.
If you don't like something, but tolerate someone doing it because they're your manager, then it's really a manifestation of power whether or not that manager is aware of it. The alternative between equals is that they either viscerally disagree or they decide to not associate with each other.