[m463]

I wonder if bad laws might be part of the problem.

If the war on drugs, civil forfeiture or even a low speed limit makes everyone resent the police, is that a root cause?

I wonder if there could be a way that the police are viewed like firemen or postal workers. Did the UK policemen that didn't carry guns have better acceptance in that respect?

[throwaway2048]

Another significant factor is police departments in the USA are almost always hyperlocal, meaning very corrupt practices can fester for a long time, all that has to happen is the sherif/police chief keeps getting re-elected.