'In the sense of what these mass murders’ espoused political beliefs/philosophies are, they’re pretty much ALL completely outside the normal mainstream of belief. That is, they don’t seem to espouse Republican or Democratic (or Libertarian or Green, or any other political party) ideals. Rather, the single biggest commonality is that they are political extremists. They come from all varieties of extremism: radical white power, nativists, neo-Christian Biblical absolutism, Islamic fundamentalism, and even complete loony things which aren’t categorizable.'  from Quora........  Please note that those "true believers" are from both the right and left.....there are extremists of all political and religious beliefs.  .....and, indeed, there's nothing quite as scary as a "true believer."  Gary Crum