That's true, I was recollecting when we had somewhat ordinary politics in USA and Affordable Care Act passed when Democrats had majority in Senate but making it single payer was stopped by purported Democrat Joe Leiberman.
Also politically impossible is that Congress made it illegal for state/federal health plans (Medicaid for poor folks and Medicaid for old folks) to negotiate prices with drug companies. Which is why it can cost $95k for a Hep C treatment in the US. It is my understanding that NHS negotiated a price around £3k for the same treatment.