Three years ago, I wrote a column explaining left-right differences on 35 different subjects. Any one or two of them would make for a major political/cultural divide. Thirty-five make the divide unbridgeable.
As the thesis itself is not really debatable, what is more difficult to explain are the roots of this divide.
I believe it is commitment to truth.
Since I began studying the left as a graduate student of communism at the Russian Institute of the Columbia School of International Affairs, of one thing I was certain: Truth is not a left-wing value. It is a liberal value, and it is a conservative value, but truth has never been a left-wing value. From Lenin to today's left, lying, especially about opponents, is morally acceptable as long as it serves the left's goals of defeating opponents and attaining more power.
Once you realize this, the divide becomes explicable.