From the POV of one who has been eased out - back in 2010, I'd been in a rock covers band for a year or so and things were looking quite good, gigs were coming in. Then they let me know no rehearsal next week, and the same the next week, and the week after that. Then the rhythm guitarist texted me to let me know I was being ditched. The politics were that the drummer and lead guitarist, who were brothers, had a mate who was a bassist, and now the band was starting to be successful, he wanted to join. The rhythm guitarist and the vocalist were rather trapped, as it was the brothers' band, and the rhythm guitarist didn't want to leave me in the dark, hence the text. All rather unpleasant for me.
Self-indulgent bit follows - please feel free to skip it.
As it happened, things turned out well for me after that, and the band I subsequently joined supported the other band at one gig. The guy who replaced me then got cancer, was himself replaced, and the replacement went on holiday just as a gig came in, so in 2016 I did a dep gig for them. And a few months ago they asked me to rejoin, and Mrs Zero ran into the wife of the lead guitarist who told her that I was the best bassist they'd ever had. However, I was settled in with the current band, and had no great desire to join a bunch of somewhat racist Leave voters as I could also see much potential for friction there.