Those who more or less ruthlessly strive to take control will use whatever religion or ideology happens to be at hand. This need not discredit the underlying ideas (e.g. the idea that all humans should be equal - obviously the winners will be "more equal"), but will often pervert their interpretation. All idealists should be very critical of their leaders.

Fundamentalism lends itself to totalitarianism, since the claim of absolute truth facilitates absolute political power. Think of the Ayatollahs in Iran.

There are other techniques of totalitarianism though, including total spying under the pretext of preventing terrorism.