First we will start out by identifying a what is meant by extremism.
Extremism (represented on both sides of the political spectrum) is any ideology or political act far outside the perceived political center of a society; or otherwise claimed to violate common moral standards. In democratic societies, individuals or groups that advocate the replacement of democracy with an authoritarian regime are usually considered to be extremists; in authoritarian societies, people who espouse democratic or otherwise liberal ideals are labelled as extremists by the ruling class or government.
Extremism is usually contrasted with moderation, and extremists with moderates (for example, in contemporary discussions in Western countries of Islam, or of Islamic political movements, it is common for there to be a heavy stress on the distinction between extremist and moderate Muslims, and it is also not uncommon to necessarily define distinctions regarding extremist Christians as opposed to moderate Christians, as in countries such as the United States).”
The term extremism is almost invariably used pejoratively, however the term may also sometimes be associated with person(s) who have different view(s) which is not consistent with the existing norm(s). It need not necessarily imply that the person is a threat to the society or the government or any other agency.Wikipedia
Barry Golcwater, the so-called “Father of American Extremism. gave an acceptance speech at the Republican National Convention that helped to lose him the Presidency against LBJ but won him to tile of the Father of Conservatism. His views are held in high regard even to the day. http://youtu.be/TFQHf16VcWo