A good exchange on the danger of arbitrary power

[noise]

MOYERS: Assume I'm president, and I'm going to say, Professor Firmage, that's all wonderful, but I deal in an ugly world. The United States is a wonderful place, relatively, because of this document, because of the values the founders inculcated in us, but the world beyond these borders is a pretty ugly world. People don't like us, people don't share those values, people are out to get us. And if I don't do the ugly things that are necessary to protect us from an ugly world, you won't be able to exercise the right of free speech out at that university."

PROFESSOR FIRMAGE: I would say poppycock, Mr. President. That is simply nonsense. The whole fight is over means, not ends. Every president with every good intention, and every tyrant, with whatever his intention, has used precisely the same argument. That is, don't constrain me by means, and I will get you there safely and well. And I think any time we accept a reason of state argument to justify means that are totally incongruent with the values of our state, we're on the high road to tyranny and we deserve to be there.

from The Secret Government by Bill Moyers

It never hurts to throw in a little fearmongering to keep the dissent to a minimum.