The demographic of those that don't contribute, either by not paying taxes or receiving more in handouts than they put into the system.
It doesn't matter if it's poor people or tax cheats or whoever...they're still not contributing, and your whole idea is everyone contributes therefore everything will be rainbows and unicorns. And gay ponies.
But since it's already widely known that you know better than the rest of us, perhaps you would be gracious enough to tell me the approximate percentage of people in our country that don't contribute, since I'm just cherry picking on some extremely rare exceptions.