What gives police, sheriffs, deputies, state troop...

What gives police, sheriffs, deputies, state troopers/state police, or anyone thats got to do with the law enforcement, the right to pull someone over & write that person a ticket for speeding? Not wearing a seatbelt? People talking/texting on they're phone, the cause of more injuries & deaths then people being murdered, robberies, breaking & entering, people killed because theyre ODed by drugs or have drank way more than the legal limit, all put together in a year. Weaving all over the road because that person is eating and drinking instead of paying attention to the road, or is messing with the laptop. Something every cop car has now, that I have seen the cop drive by me fooling with while he was driving. Or driving wrecklessly? What about the ones that are bad about running stop signs and traffic lights? What gives cops the right to pull someone over when cops do all those things they're selves? If not worse. What about the cops that also do drugs and are alcoholics. And do that stuff both on & off duty. Do those cops ever have take the same drug & alcoholic tests that civilians do? Is it because they're wearing a badge on they're chest, has a gun on one hip and hand cuffs on the other, that that makes them think they're above the law and can do/get away with things that a civilian can't? Iv always thought that the law enforcement are the ones that's supposed to set the example(s) for the public. And have to go by the same laws that everyone else has to go by?