I'd say it's even simpler than that, it's just tribalism.

$person has criticized our gracious $monarch. They deserve to die!

$person speaks against $religion and is a heretic. They deserve to die!

$person made fun of $fascist_leader. They deserve to die!

$person goes against $party. They deserve to die!

Whoever is in power speaks absolute truth. Be it a fascist leader, a church, a communist party or a monarch. Opposing that truth is heresy/treason/counter-revolutionary/evil and should be severely punished.