There are large sections of the American populace who think that access to social support is zero-sum and universal access takes something from A if B also gets

There are large sections of the American populace who think that access to social support is zero-sum and universal access takes something from A if B also gets it. So while we have had Medicare and Medicaid for quite some time, the discussion has been resistant to actual universal health care largely due to these factors. You're right that that's changing, but the question being "WTF, America?" about why it's still not a thing is pretty valid to me. Put another way: it's been proven out, and to me pretty inarguably, that conservative Americans are pretty OK with socialism for themselves and for people like them--this is the genesis of the whole "keep the government out of my Medicare" meme, because it's real. And to people who adopt that workview, providing the same services to people who are unlike them codes as giving things to "undeserving" people. This remains true even as the "center" moves somewhat leftward and universal healthcare discussion becomes a tenable option in the Overton window--even many people in favor of things like UHC are in favor of UHC for themselves, not for everyone. Asking "what's wrong with you that you let this happen?" is, to me, quite fair.