For the most part, I agree with your position, Golbez. Politicians, as a professional class, have about as much integrity and dignity as a pack of starving hyenas.
As a class, mind you. There are individuals who stand apart from the pack, in crucial moments of history, and make the principled stands that tend to define history.
I won't bore anyone with a list of such Americans, but if you know any American history, you already know the main players.