MashGet

Extremist from WikiPedia:

Extremism is a term used to describe the actions or ideologies of individuals or groups outside the perceived political center of a society; or otherwise claimed to violate common moral standards. In democratic societies, individuals or groups which advocate that democracy should be replaced with some kind of authoritarian regime are usually branded extremists.

The term is invariably, or almost invariably, used pejoratively. 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. 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).

Read more on WikiPedia