Being a police officer is one tough job. I'm using the term "police" here to include the entire law enforcement community: several kinds of feds, state troopers, as well as county sheriffs and city police too.
Imagine a life in which you deal daily with society's violent misfits and losers, and the upstanding people you meet at work are mostly victims and other police. Add to this the complication of being on round-the-clock shift work, which makes maintaining relationships with 8-to-5 'civilians' difficult. For these and other reasons, sociologists tell us police mostly have other police as friends.
So, these men and women have a hard and somewhat isolating job, keeping society safe for the rest of us. Our police sure as heck don't need the President making that job harder; something that just happened with l'affaire Gates.
We need to cut the police some slack, instead of the other way 'round.