What people don't understand is that a non-trivial number of humans (~1-2%) are born without the mechanisms of shame and guilt that most of us have. This condition is called psychopathy, but not all psychopaths are Ted Bundy/Jeffrey Dahmer types; those are termed "unsuccessful psychopaths."
The vast majority of psychopaths learn to mimic the emotions they know they are supposed to be feeling. In a deep and real sense, and through no fault of their own, their lives are decades-long series of lies.
You can imagine what an advantage psychopathy would be in business, politics, or any other competitive environment involving complex human interactions. In extreme cases a psychopath literally has no guilt about hurting other people in ways trivial or not so trivial; their only restraint is self-preservation, the fear of getting caught.
We're learning a lot about the human brain these days, and one thing we're going to discover is that many of our politicians are psychopaths. Think of Cheney giving a stand-down order on 9/11 not to shoot down the plane that was aimed at the Pentagon, knowing dozens or hundreds of people were about to be killed in that building. Could you do anything so cold-blooded? Or Bush sending soldiers off to kill; Mukasey accepting torture; Chertoff building his FEMA camps. All of them lying effortlessly, with an ease that is so foreign to most of us that we can't even believe it's true, even though we all know in our hearts that most politicians are congenital liars.
Now you see how McCain is willing to kill these thousands of people for -- what? A little money, a little personal glory?
Our political system screens for psychopaths, for people who want power so much that they are willing to do or say anything to get it. We all instinctively know this is true, yet we still can't quite believe it.
But there it is -- we are ruled by madmen, and so are most countries around the world.
http://en.wikipedia.org/wiki/The_Mask_of_Sanity
"In these vignettes, Cleckley presents a typical psychopath's behavior. For example, the psychopath's ability to tell vivid, lifelike, plausible stories that are completely fraudulent, without evincing any element of delusion. When confronted with a lie, he is unbothered and can often effortlessly pass it off as a joke."
