J. S. Mill time!
There is a book - currently (though perhaps not for long) freely available on the internet - called On Liberty.
It was published in 1859 and it was written by British philosopher John Stuart Mill.
It would be quite good - I think - if all people desiring to hold office, were to read and understand it.
In it we find grand gems of wisdom, such as:
"If a person possesses any tolerable amount of common sense and experience, his own mode of laying out his existence is the best, not because it is the best in itself, but because it is his own mode. Human beings are not like sheep; and even sheep are not undistinguishably alike. A man cannot get a coat or a pair of boots to fit him, unless they are either made to his measure, or he has a whole warehouseful to choose from: and is it easier to fit him with a life than with a coat, or are human beings more like one another in their whole physical and spiritual conformation than in the shape of their feet?"
As far as extremism and the silencing of opinions is concerned:
"But the peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error."
We do no one any favours by blocking out opinions and views. Instead we (our "extremist" counterparts) should clash those opinions in an effort to find truth or a common ground. If views are never tested then we are never given the chance of exchanging them for other views or of spreading the views because they've been tested.
Quotes taken from: http://www.billstclair.com/Serendipity/on_lib.html
Coat icon because a coat is apparently more complex than a human life in the view of some people.