> Either the system we have today works because we put enough money into it, and therefore would continue to work if we nationalized; or our system has unjust failures that we should seek to rectify.

That is very bad reasoning. Most things don't get cheaper when they get nationalized. There is some evidence healthcare may be different in this regard, but the point is: costs are not invariant under nationalization.

> Is your position that bringing everyone's healthcare up to Medicare's baseline is too expensive? Where is the extra cost coming from?

Cost of providing the existing service is not the only cost worth considering. The other issue is opportunity cost of innovation. Right now there are powerful incentives for people to innovate in the healthcare space, particularly in pharmaceuticals. But also in prosthetics and the procedural space. Nationalization is likely to crimp those incentives, and thereby lead to less innovation over time.