This view of police is incredibly pervasive. But again, we also need to talk about the other half of the mythos. That there are hordes or dangerous black and brown "villains" just waiting to victimize good white folks. https://twitter.com/jbouie/status/1273563993785892864
The two halves of this fallacy work *together* to enable violent oppression. You can't just have heroes. Heroes have to be noble. You have to also paint a picture of how "evil" the enemy is. That justifies the heroes being violent because it is painted as a *response*.
A huge part of white supremacy is keeping white people on fear of The Other as a justification for giving more power to those in charge. Police "need" this budget, this militarization, this immunity from prosecution. If they don't have this power, white people feel less "safe".