Radical

From dKosopedia

The term radical, as applied to political theory and ideology, denotes someone who believes in an ideology or theory that doesn't accept the status quo of society as natural, apolitical, or the way things should be simply by virtue of being the way things are. Virtually all radical ideologies and theories seek to challenge the status quo, to question how things came to be as they are, why they came to be this way, and whose interest things being this way serves.

Most, though not all, radical ideologies and theories also argue that the status quo cannot be fixed by piecemeal reforms and that a more fundamental restructuring of society is necessary to achieve their goals. This may include advocating the armed overthrow of the existing social structure, as in Marxist-Leninism, but often also takes other forms such as many modern socialists who advocate for a democratic means of revolution.