That's funny, because neither Vermont nor California cited "logistical problems" as the reason they didn't pass single payer. The reason it failed in both cases was because the tax increases necessary to fund it were so high they even made progressives sick.
For the record, I've
never supported "single payer" as an option and that's part of the reason. If we'd started with that decades ago, we'd have adjusted to paying for healthcare through taxes versus insurance premiums. Doing it now is a shock, even if overall the change is a wash. Those changes to single payer will have lots of winners and losers, even if on 'average' there's no change in costs. It's worse if only one or a few states impose the high taxes on individuals and companies. The losers from those high taxes, whose taxes are higher than what they're now paying in premiums, have a big incentive to leave or avoid CA. If it's nationwide the problem is far less.
I also don't really believe the taxes should be limited to income taxes. If you fund broad based benefits, the taxes are appropriately in my view broad based taxes. It's why in part that Europe and many other places have high VAT or consumption taxes - to fund things like UHC, and I'm fine with using consumption taxes to do that. Everyone pays part of the cost, and everyone gets a benefit. But, again, there are serious competitive issues when a VAT or RST is 20% in CA, and only 8% in Nevada.
And the promise is lower costs, because a single payer can drive down those costs. But in a national economy and national healthcare system, it's incredibly difficult to have one hospital getting paid $400 for X and across the road or across the state line a different hospital is getting paid $650 or $1,200 for X. Same thing for doctors. My brother is a doctor in CA. He's paid a bit less than he could make elsewhere, but it's in the ballpark. If we really controlled costs, maybe his pay is half what it is now. Well, if he can make 100X in CA and 200X in Washington state, that's a pretty big incentive to leave CA for Washington.
Anyway, the only possible way we'll get "single payer" is if it's done nationally, and I don't think it can be done nationally, not realistically. So I don't support it, and IMO most politicians who say they do are just using support for 'single payer' either dishonestly, or as a marker for UHC which is entirely different. Worldwide, "single payer" like Canada or a government healthcare plan like the UK are the exceptions, but every other country has UHC, and they get there dozens of ways. Most places have mixed funding, like we do here. A large government role, and with employers and employees paying for lots of the total costs with taxes or premiums, some private providers, some government facilities. I can't envision a scenario where we put private insurers out of business and convert to a nationwide Medicare for all system. The transition is too great, the disruption to so many relationships, such as employer/employee too great. It's why I support the ACA as the least bad of the options I've seen.