This election has brought to the fore an issue of great concern to me.  We are so divided in our support for so called "liberal" vs. "conservative" ideals.  I never thought people were all that different.  We all believe in freedom, punishing crime, nationalism, capitalism and family.  So, why is it that we have such vehement disagreements on the subtle differences.  

I searched on the web and found the below, but it still does not explain to me why the magnitude of our disagreements is so profound.

THE LIBERAL PHILOSOPHICAL SYSTEM

EPISTEMOLOGY: Reason. Knowledge comes from human beings. "Inalienable rights" are innate in human beings, as a result of their being reasoning beings.

METAPHYSICS: Subjective reality. Liberals don't believe that what is true for one person is true for another person.

EHTICS: Do things for the good of society as a whole. Liberals place more importance on society as a whole instead of individuals. Helping the less fortunate is also important. Liberals deal with people in groups rather than as individuals.

ECONOMICS: Socialism. Liberals believe that an uneven distribution of wealth is not ethical, so another mechanism -- in this case, the state -- must allocate that wealth.

AGENCY: Determinism. Liberals believe that things happen outside the control of human beings and that they have no control of what occurs in the world.

THE CONSERVATIVE PHILOSOPHICAL SYSTEM

EPISTEMOLOGY: God. "Inalienable rights" come from God, who created human beings and gave them the capacity to reason.

METAPHYSICS: Objective reality. There is a knowable truth that is universal for all people (this truth, incidentally, is usually the same as the politician's truth).

ETHICS: Self-interest. A thing should be done by an individual for the good of that individual. Things done for the good of the individual will necessarily be done for the good of society (Adam Smith's "invisible hand").

ECONOMICS: Capitalism. Conservatives believe that capitalism is the most just of all the economic systems. A person should work for what he earns and nothing less or more.

AGENCY: Free will. There exists nothing outside the control of a human being's free will. There are no excuses because everything is the result of a person's good or bad choices.

For the list given, for myself, I have a difference of opinion about the metaphysics.

Reality is not subjective. But it's too large and complex and far beyond human ability to comprehend. We're not equipped with our minds or senses to do it-- at all. So, while reality is objective, our approach must be subjective.

Now, what causes the split to be so total? I would say that both outlooks require one or several core opinions we form early in life, which are basic to our social reasoning. The rest of the opinions manifested are rigidly assembled by adulthood using those basic opinions as the foundation.

They are fit together like Legos and don't change unless the underlying, hidden opinions change. These are so deeply set in the personality that they are much too traumatic to change.

So, only a trauma might change them, and cause them to be re-examined. It was remarkable to see many liberals change to conservatives after 9/11.
I'm thinking that many war veterans change their opinions on a wide range of social reasoning.