Well, lo and Behold! Someone else has written it for me. Some of my favorite graphs:
[H]ow much truth is valued may be different for the right and the left.
In the hierarchy of leftist (as opposed to traditional liberal) values, truth is below other values, such as equality, opposition to war, the promotion of secularism and a number of other highly regarded values on the left.
This does not mean that the number of truth-tellers among individuals on the left is necessarily smaller than the number of individual truth-tellers on the right. It means that truth-telling is not high on the left's list of values.
Few liberal activist groups tell the truth. Not because their members are liars — in private life they may well be as honest as anyone else — but because whatever the left advocates it deems more important than truth.
This does not mean the right is always honest. For example, conservatives who say that "pornography causes rape" are doing what the left does — putting their agenda, in this case a loathing of pornography, above truth-telling. I have seen no credible statistics linking the proliferation of pornography with increased rape.
Read the whole thing, it will be worth your while. It does raise an interesting issue though. If one side values the truth, and the other feels that the means justify the ends, can there ever be a fair debate?