Humans are an imaginative bunch. We can think all sorts of things beyond what actually exists. For that, we have been able to make certain improvements in our lives. We had to imagine automobiles and air planes before we had them. Our creativity has paid off in many respects. But, sometimes we lose our sense of realty when we think creatively. There are certain characteristics of humans that despite our desire to change them for the better, they cannot. I have had dreams in which I could fly just by willing myself to do so. But I never actually will be able to do so. The reality of physics prevents it. The reality of being human also prevents us from achieving Utopian ideals for society as well. There are some realities associated with being human (our frailty, and our obvious imperfections, to begin with) such as that prevent politicians, and really, any group of people from achieving true civility, compassion, and community, will always be with us. In the bible, such lack of perfection is referred to as "sin" - something we are born with, and something we will never be able to rid ourselves of.
The one big problem with striving to become a more civilized people is that at some point we reach our full potential of civility and yet still fall short of what we imagine we could be, we are less than completely civil. To compensate between what we are and what we hoped to be we begin telling ourselves little lies about how civil we are. We become two faced, saying one thing, and doing, being something else. Eventually we start believing those lies about our selves and how civil we "think" we are. And that leads us to such things as voting for someone like George W Bush, who declared himself "pro life" so to win votes necessary to achieve the most power position in the land, and yet he has more spilled blood on his hands than most any other human in recent memory. Even before becoming president he was Government over a state the the most executions in the country. The truth about him not actually being "pro life" was there for everyone to see, but the lies they've been telling themselves blinded them from the ugly truth.