The class war doesn't need a spark. It has been going on for hundreds, if not thousands, of years. Except usually most people pretended to ignore it and didn't participate. Now it's [once again] getting really difficult to ignore it, so there's little choice but to participate.

Standard societal cycle of the elite class enjoying some 200 years of comfortable life, then going too far and getting pushed back. Though as time goes on, each cycle seems to be shorter. Maybe some time in the future it'll be gone entirely?