It's not that we now have more people with strange ideas than we have had in the past. It's just that today's political and social attitudes make it easier for these people to sound off and be heard.
Extremism can be difficult to define.
Extremism can come from either the liberal or conservative side of the political spectrum or could well be apolitical in nature. One can't help but wonder if there's anything else in their lives that means anything to them. The ones that I really can't figure out, however, are the animal-rights activists. Nature is not a kind place. The sick, weak, and less capable do not last long.