The author of this commentary brings up a few examples of things such as abolition of slavery, racial equality and women’s suffrage that at one point in the past were all technically extremist positions. Yet today any support for things like slavery, segregation or not allowing someone to vote based on their gender would be regarded as morally abhorrent by the overwhelming majority of people in our society.

By Michael Kazin - October 30, 2013

American politics is a famously contentious theater, especially today. But the vast majority of liberals, conservatives, and Washington journalists all seem to agree that “extremism” is appalling and should be eradicated.

Yet the meaning of the term is as prey to ideological dispute as are such holy words in our political lexicon as “freedom” and “rights.” Conservatives call Bill de Blasio, who is about to be elected mayor of the nation’s largest city, a “left-wing extremist,” while liberals counter that anyone with ties to the Tea Party is an “extreme right-winger.” “Extremist” is the description of choice for fundamentalists of any religion, unless, of course, you belong to one of the faiths being gored. In that case, it’s only traditionalists from the other religions who are “extreme.” “Community,” the literary critic Raymond Williams once observed, “seems never to be used unfavorably.” But no one has a kind word to say for extremism or extremists.

Well, let me be the first. Sometimes, those who take an inflexible, radical position hasten a purpose that years later is widely hailed as legitimate and just. Extremism is the coin of conviction, whether virtuous or malign. It forces middle-roaders to crush the disrupter or adapt.

Read More At Dissent

I was originally alerted to this commentary here

In addition to what Kazin wrote, Ed Brayton asks an important question, I think we should all think about after reading the commentary.

So when is extremism good and when is it bad?