Quoted: Actually they were Libertarian extremists, believing that all governmental power was ultimately derived from the consent of the governed. Hence, the reason the constitution had to be ratified by the popularly elected legislatures of the various states.

They weren't concerned about creating a perfect society, in which everybody got free medical care and government managed retirement.  They wanted to created a FREE society, in which every man had the freedom to manage his own life without undue meddling from government and other busybodies.  Life's imperfect and so is a society based upon freedom.
Modern Liberals aren't consistant with the mindset of the FFs, no matter how they spin it.