Some men are moral - our founders were moral. But no man is perfectly moral because men are basically evil. That's why we all need a Savior. You are focusing on man and you will not be able to discern moral absolutes from observing man, becuase they come from God. However, each man has the laws of God written on his heart - each man has that little voice that says "I shouldn't do that" or "this is wrong".
As you say, there are definitely moral values that we SHOULD all follow, but man does not. Once again, as you say, moral relativism is the dominant system in the world, and has been throughout history. I don't see how you can define something as an absolute, when history has proven that it is never achieved. Where and what is the absoluteness of something that is never achieved? I believe the desire for moral absolutes is an absolute in itself, but there are no absolutes when dealing with the moral BEHAVIOR of man.
You are right that moral relativism has always been the dominant system of the world, but you are wrong in saying it has never been achieved. Our founders established a nation and government based on moral absolutes and liberty and freedom (unique in history of mankind), but since that time, evil forces in America seek to destroy it and turn it into a dictatorship. Evil will always try to destroy what is good - darkness hates light.