Hmm, I actually disagree that extremists should only be those who want to go outside the system and use violence. I would also find trying to effectively and knowingly go against the 1st amendment extreme too. I think that extremists also need to be kind of at the… extremes of a political spectrum also. In fact, I do find it useful (maybe we need a different term) for a way to talk about if someone is in a very edge AND niche position of their group.