So on one hand you would bust someone for a joint "maybe yes maybe no" but on the other hand you don't make the laws you just enforce them? You say you use discretion, then later you say you just "enforce the law," which is it?
You don't protect my freedoms, you infringe upon them. I don't feel any safer with arrogant assholes like you armed with guns. More legislation and reliance upon police has only decreased the average american's freedom and ability to defend him or herself. People fear retribution if they shoot an intruder.
You overvalue the police force's contribution to society severely. I see deaths from psychotic assholes arresting someone for an open container, I see a kindergartner and a grandmother being tasered, I see a man being beaten with flashlights on national TV by a group of police. You want to generalize? I can too. Authority (especially when given to those actively seeking it) spawns corruption and abuse, I take a minimalistic approach, they are given far too much leeway, and FAR too much credit.
You probably think prohibition was a good idea, outlawing alcohol really decreased society's problems.
And BTW, I've never been arrested for drugs, and only had one speeding ticket, so drop the vendetta thing.