I have a friend I haven't seen since high school, though I'm connected with him on Facebook. He will outright tell you himself that he's a communist—familiar with the writings of Marx, etc. We could not be more diametrically opposed. However, he's as clear-eyed as you seem to be.
I suspect that most people simply aren't all that intellectually curious. I don't remember if Haidt explicitly mentioned this, but I think somewhere either he or someone commenting on his study asserted that it is much easier to pick up the party line of liberals through osmosis, since those in education, the media, and so forth tend to be liberal. So, even conservatives are more readily exposed to the liberal take on things. Liberals on the other hand are not.
But the point I'm making by mentioning my friend and thanking you is that I suspect that people who are intellectually curious are more or less inoculated against mischaracterizing the side they disagree with, since they don't learn almost exclusively through osmosis.
I appreciate your contribution to this thread.