Try this one: every US citizen child born after January 1, 2027 is covered by the national health program. Not their parent's employer's program, or CHIP, or state Medicaid. In 65 years, everyone else has either died, or gone on Medicare. Fund the program with a VAT that increases as needed, to cover costs.

Never get approved and wouldn't be stable if it were. Current adults who are struggling to pay for their own health care aren't going to be willing to tax themselves to pay for someone else's health care - especially people who are perfectly capable of paying their own way. The resentment would be massive among folks close to the dividing line - in 20 years, the 20 year old who has to pay full freight for their own health care (and pay into Medicare, still) is going to be deeply upset that the person born a few months before them gets a free ride for the second biggest expense they have in their life (behind housing).

It's not infeasible because of a law of nature or anything like that, any more than it violates the laws of physics to switch the country to 220V. It's just never going to garner enough support to happen.