It's a nice sentence, but he cribbed it from Daniel Webster:
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern well, but they mean to govern. They promise to be good masters, but they mean to be masters.
-Daniel Webster
"Government is not reason, it is not eloquence. It is force, and like fire, it is a dangerous servant and a fearful master."
George Washington
And this:
"There is danger from all men. The only maxim of a free government ought to be to trust no man living with power to endanger the public liberty."
John Adams
And my PERSONAL favorite:
"Necessity is the plea of every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves."
William Pitt