Every man who has been in practical politics grows to realize that politicians, big and little, are no more all of them bad than they are all of them good.
 Theodore Roosevelt, Theodore Roosevelt; an Autobiography (1913). copy citation

Context

“All his transgressions that he hath committed, they shall not be mentioned unto him: in his righteousness that he hath done he shall live. Have I any pleasure at all that the wicked should die? saith the Lord God; and not that he should return from his ways and live?" Every man who has been in practical politics grows to realize that politicians, big and little, are no more all of them bad than they are all of them good. Many of these men are very bad men indeed, but there are others among them—and some among those held up to special obloquy, too—who, even although they may have done much that is evil, also show traits of sterling worth which many of their critics wholly lack.” source