Barbara Boxer is not a bitch or the "C" word.

[Hortensis]

46. They are not. They are very well established, old

respectable liberal and progressive government concepts and realities depending on where one is.

But that is not what I'm talking about. Which, btw, is also is well established, at least as well as anything in this world of exploding knowledge can be expected to be.

Introduction to Political Psychology: 3rd Edition
Political Psychology: Neuroscience, Genetics, and Politics
Extremism and the Psychology of Uncertainty
The Oxford Handbook of Political Psychology: Second Edition
The Rationalizing Voter (Cambridge Studies in Public Opinion and Political Psychology)
Affective Intelligence and Political Judgment
The Political Brain: The Role of Emotion in Deciding the Fate of the Nation

I quickly grabbed this little list off the web, deleting Jihad, Islam, and terrorism/terrorist to keep it closer to DU home, but of course there is incredibly more published in these disciplines. In the interest of disclosure, I have not read these particular books, although I have one very well regarded interdisciplinary book, and some are pretty expensive, but fwiw I did have a unit on political psychology 40 years ago.

Extremism is very real, if amorphous and sometimes hard to define. And we pretend it is not literally at our peril, for some I am coming to suspect literally at the peril of their ability to think rationally on political topics.