>>Single-payer is ideologically anathema to libertarians

For Libertarians (LP), maybe. There are plenty of libertarians who see initiatives like single-payer and UBI as the only way to reduce graft and overspending of the federal government, knowing that pure elimination is impossible.

Can you really be a libertarian, even with a small 'l', and support single-payer?

Yes, if you combine it with reducing absurd controls of the industry. Libertarians tend to be angry about the fact that Americans cannot buy medicine abroad, that medical schools are absurdly regulated, coupling insurance with jobs, and so forth. Single-payer + those reforms are well within a reasonable libertarian platform.

https://www.google.com/search?q=libertarians+who+support+sin...

I'm not an expert on libertarianism, but I looked at the first results from that search and it seems like some libertarians support some form of single-payer but purely as a political compromise, which I assume is what you were referring to. It still doesn't jibe with the ideology, but they seem to think that certain forms of single-payer might be better than what exists now.

Yeah, pretty much. I used to be a libertarian and know a lot of people who are, and many regard it as a reasonable compromise and a strict upgrade over the nonsense we have now.

Not really. Advocates of any ideology can compromise their ideals pragmatically, but libertarians explicitly cannot countenance single-payer as an end state. The idea of a government-run monopoly on health care is directly contrary to libertarianism.

Which is what you see when you read posts from libertarians about single-payer. Single-payer as a compromise, and only if accompanied by such a radical deregulation of medicine that "single-payer" is really just an economic subsidy for consumers on a private marketplace. That's a coherent (if, to me, terrifying) plan, but it's not what mainstream policy thinkers mean by single-payer!

Again: I'm not saying a libertarian can't accept single-payer as a temporary compromise (even for very long definitions of "temporary"). But if you find single-payer attractive, you're an economic liberal.

People don't throw the word "monopsony" around as much, so people aren't as afraid of them.

ACA is structurally designed to be a stepping stone to a more rational system. I don't think you'll find a lot of ACA boosters who think healthcare in the US is a solved problem because of it.

It's not a stepping-stone towards single-payer.