All "isms" are fundamentalist in nature, not religious.
Science can be just as dogmatic and fundamentalist as something based on pure faith.
There are facts and what we know...a small set.
Or there are non facts and what we don't actually know...a very large set.
The fundamentalist is certain that their "facts" or "faith" are not only right, but also right for others.
This is not religious in nature, as you will find fundamentalist thinking in any person/group who thinks their way is right, and necessary for others.
Call it an ego problem, and an ego that is not content on its own, but needs to show others that they are wrong...not using logic or reason, but emotion and force.
Religions are not political, but political people use religions to advance their politics.
Politics are generally just an extension of someone's fundamentalist beliefs as they relate to the way others behave.
Sexual politics, family politics, business politics, government politics, religious politics.
They are all manifestations of the same thing.
Even the libertarians suffer from this disease, as they not only think libertarianism is right for themselves, they think it should be right for everyone else.
That's the key...thinking it is right for oneself, and trying to push others to that same conclusion...and doing it with not only an intellectual certainty, but a gut level feeling of certainty.
Quote from Ricter:
All of our "isms" are religious in nature. Their fundamental premises can only be accepted on faith.