If you buy into the pessimism, you and your descendants are doomed. You become the people the founders warned us against.
Founding Fathers Quotes: (didn't see any warning's from them like you describe though....?)
Remember democracy never lasts long. It soon wastes, exhausts, and murders itself. There never was a democracy yet that did not commit suicide. Patrick Henry
The truth is, all might be free if they valued freedom, and defended it as they ought. Samuel Adams
If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen. Samuel Adams
Rebellion to tyrants is obedience to God. Benjamin Franklin
During the course of administration, and in order to disturb it, the artillery of the press has been leveled against us, charged with whatsoever its licentiousness could devise or dare. These abuses of an institution so important to freedom and science are deeply to be regretted, inasmuch as they tend to lessen its usefulness and to sap its safety. Thomas Jefferson
I have sworn upon the alter of God eternal hostility against every form of tyranny over the mind of man. Thomas Jefferson
The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. Thomas Jefferson