Yes, there are two linked factors. Supervisory declines that allowed the bullies and the bullied to engage without control. This control was teacher/hall monitor overwatch. Bullies were empowered by the loss of supervisory overwatch engendered by fools in power. The overwatchers were beaten back by litigious parents who were the fools.
When I was a kid in the UK in a public school there was a kid mediated, class segregated supervisory milieu that allowed no weapons, no kicking, limited fights as senior boys were empowered to stop fights... It was a mini 'Lord of the flies' scenario with limits. What I see in US schools is rampant persistent bullying with NO RECOURSE. Teachers do not stop it because the kids they may try to stop are as big as they are in many cases and often carry knives or 'chucks.
I hear stories about inner city drug/gun chaos.
Kids with no recourse go home and get their father's guns and seek the only recourse left to them.