Today, there shall be gnashing of teeth and brandishing AR-15's for the Combating Terrorism Center at West Point, hath released a study entitled
Challengers from the Sidelines: Understanding America’s Violent Far-Right
This document was published November 2012
The author, Arlie Perliger, discusses the Ideologies of various Far-Right extremist organizations from the KKK to the "Identity" Movement to the violence in the "pro-life" movement, timelining them from 1865 - 2000.
The document is heavily footnoted and written in a clear, concise manner that puts it points across quite succinctly. The document also points out how deeply anti-Semitism in ingrained in these movements.
Perliger has found a steady increase in attacks from the Far-Right since 1980
These findings suggest that, in general, far-right groups and individuals are more inclined to engage in violence in a contentious political climate. This helps to explain the lack of increase in the level of violence 1996, the least-competitive elections of the last 22 years. Several possible explanations may be offered: (1) Far-right groups assume that during election years the public is more receptive to political messages, including those conveyed via violent activism; (2) The competitive nature of the political environment during election years encourages engagement in political activism (see also Chenoweth, 2010) and provides more resources and opportunities; (3) The inability of far-right groups to penetrate the political system via legitimate means, as well as the marginality of their ideas, is even more sharply emphasized during electoral years. This further encourages the use of alternative means to promote their ideological agenda.
[emphasis mine]
There is so much clear-eyed, level-headed goodness in this document, that I'd risk running afoul of Fair Use, if I were to quote more. So, here is the link to the PDF