I have a liberal friend who hates extremism (sort of an extreme position in itself).
I advise him that people who hold extreme positions may be right or may be wrong. Abolitionists were extreme in their hatred of slavery. Was that an improper position to profess? The Founding Fathers were extremists in their philosophy towards liberty. Does anyone wish our fellow Americans held such extremist views today? What about the failure of moderate Germans to stand up to Hitler (I apologize for the Hitler-Nazi allusion but Jews have a complex about that historical example).
Jonah Goldberg discusses this in "The Case For Extremism" and provides us the great Barry Goldwater quote:
I would remind you that extremism in the defense of liberty is no vice. Let me remind you also that moderation in the pursuit of justice is no virtue.
Martin Luther King from his letter from the Birmingham jail:
"So the question is not whether we will be extremists, but what kind of extremists we will be. Will we be extremists for hate or for love? Will we be extremists for the preservation of injustice or for the extension of justice?"
I am for extremists for free markets and personal liberty.