I think the "entitlement" argument can be easily refuted by telling your interlocutor they're not entitled to you having children, and if they want America to have a million more children they should have them themselves.
This ties into my own theory about all this: for the first time in history, it's so socially okay to be child free.
At any other time, it was assumed that if you got to a certain age and didn't have, it was a problem. We've finally mostly gotten over that hurdle (at a high level, not necessarily within close-knit groups and families), and people act surprised that many of us never wanted them to begin with.