Born in 1955 in South Carolina as I grew up, folks I knew and I, saw the police as 'good guys' and the level of violence even in the poorest neighborhoods of any racial make-up was nil compared to today. Despite the lingering segregation and civil rights issues of the day life in America was more peaceful fewer guns and about one fifth as many Americans in jail (per capita) as today.
Then (I can see clearly in retrospect) the Vietnam War protests and open use of marijuana by protestors scared the living shit out the 'authorities' in America from dog-catcher to the president of the USA. Suddenly the powers that be linked war protests with communism and revolution and that with drugs and so began the 'War On Drugs'. Suddenly, millions of random acts of inebriation using pot or cocaine became jail-able offenses whereas before they would have called for just a slap on the wrist by authorities and only that when done publicly.
This began our society's spiral downward into the hateful chaos we see today. More drug arrests led to more funding of investigations led to more incarcerations more prisons more money money money into the drug war. Now the police are no longer loved and respected, but hated and feared. They are no longer peace-keepers but storm troopers who see the general public as the enemy. After-all it is well known that a very high percentage of Americans do use some illegal drug or drink illegally.
Today, to the police, we, Americans are the enemy.