"The American idea" includes virtues like justice and charity, but those virtues were to be exercised predominantly by the civil society, NOT by a "Big Brother" leviathan government. (I assume here that they are not using "justice" in the strictest legal sense of the term.)
The founders knew that governments and the individuals positioned within them were inherently NOT virtuous for the most part, so to have government "exercise virtues" was unrealistic and self-defeating from the perspective of the citizenry as a whole.
There is little to be said in favor of Sachs' ideology; it's been proven time and again throughout history to lead to tyranny and repression.
Just don't see the need for further debate. Sachs is dead wrong. The American founders got it right.
The legal, contractual, compact theory of Government to secure the basic Natural Rights--those which Man has in a State of Nature--is not something that must inevitably either affirm or deny, such virtues as justice, charity or a healthy sense of community (something we have really begun to lose in America).
While the social virtues that thrive in the society of a people motivated by religious values, are correctly seen as beyond merely important to the health of a social or political order; understanding those virtues--and what they mean to the social order--is not helped by seeing them as some sort of alternative to our traditional recognition of the Natural Rights of Man. Quite the contrary. There can be no "justice," that ignores the rights--including the free will of the individual in the pursuit of truth--that Man has from the very nature of the creature.
It cannot be over-stressed, in my opinion, that American principles grew out of actual experience & reason, in sharp contrast to the fantasy wish lists that drive every form of Socialist meddling with the natural development of a social order.
Thus, charity is a giving of oneself to help another. It is not, by any reasonable interpretation, a situation where you discover a need, and say, "Wait a moment, while I go rob my neighbor for your benefit"--either literally or via counting a leftist mob at the polls.
Understand that Welfare in Jefferson's Day worked, because it was not confused with the role of Government. That does not mean that it was not important, valuable, etc..
We need both raiment & shelter; both food & sleep. They are not the same thing; nor are they alternatives in the ultimate sense.