And to be fair...I think that Mark Steyn borrowed the sentiment if not the line for Ronald Reagan.
Right you are. As far as I know its first appearance came in Reagan's 1981 Inaugural, although it could've been a carryover from a previous speech. See Paragraph 13:
So, as we begin, let us take inventory. We are a nation that has a government—not the other way around. And this makes us special among the nations of the Earth. Our Government has no power except that granted it by the people. It is time to check and reverse the growth of government which shows signs of having grown beyond the consent of the governed.
My favorite passage is three paragraphs up (Para. 10):
From time to time, we have been tempted to believe that society has become too complex to be managed by self-rule, that government by an elite group is superior to government for, by, and of the people. But if no one among us is capable of governing himself, then who among us has the capacity to govern someone else?