How does subsidizing unproductive people, enhance the "welfare" of the United States?

Concerning what the previous answerer says, we could take those same babies and turn them into slaves and use their labor to promote the welfare of the United States. The factor here is what is moral to do, not what merely promotes welfare of the country. In the case of welfare, that is supposed to be a state issue and not even concerned with the Constitution of the United States. So no, food stamps and free education are irrelevant via the Tenth Amendment.