Its a show of force. The people that are supposed to "Protect and Serve" the community, actually become robot goons for the power brokers.
They become tax collectors, first and foremost, issuing tickets for stupid infractions, enforcing codes such as registration violations and "safety violations" like a busted taillight, then they become soldiers for the state. They come into people's homes for non-violent, victimless crimes and put guns in their faces. They raid and steal, impound and seize... They have all the power they need. They can use violence legally and we can't.
Now, its not to be said that they're completely corrupt, as all one has to do is go to Mexico to get a taste of that, but the fact remains that they are no longer "protectors and servers" of the community, but mere robotic operatives of the state.
But the sad truth is that any society needs a police force, and ultimately, the power they have, as with any authority, whether its the police, the judicial, the legislative, or the executive, the power becomes the end, rather than the means.
Imprisoning the amount of people we do, for non-violent, victimless "crimes", that is, things the government has decided we are not allowed to do, is a crime in and of itself.
The injustice this government does to its own people far, far outweights any justice it does acheive.
And you, wise guy, want it to have more power. You, wise guy, scoff at us libertarians who merely wish to have the government play the role it was Constitutionally empowered to do. You feign shock at abuses of power, when you want to give them MORE and MORE power. But, you're till a pretty cool guy, so don't start hatin on me.