I've never understood this ancestor-worship of our Founding Fathers (and that's exactly what it is).
Our Founding Fathers owned slaves, disenfranchised women, embargoed the entire world, went to war for silly reasons, committed genocide against Native Americans, and had temper tantrums at mild tax increases. For many of them, even their support for representative democracy or checks and balances was wavering at best.
The Constitution was basically a compromise that was cobbled together from the various ideas that were floating around at one particular moment in time 221 years ago. Anyone who think it's perfect or even close to perfect is deluding themselves.
Some of their ideas can be built upon. Some of their ideas were just ridiculous and have no place in the United States of 2010, which (if you haven't noticed) has changed a bit since 1789.