I think the evidence is quite clear that universal health care reduces aggregate costs, but the public cost in aggregate is enormous.
1. This means large new taxes for everyone. For those on lower incomes, they might end up better off. For those on middle-upper+ incomes, they will unequivocally end up paying more.
2. The U.S. already has unbelievably high deficits and debt. This would make that worse without significant spending cuts elsewhere, and without very large new taxes. And before someone says "just tax the rich!", even if every billionaire in the U.S. had all their wealthy confiscated today, it would barely cover U.S. federal spending for *one year.* Then the party's over and the government collapses. "Just tax the rich" is an absurdly superficial position. European taxation is broad and deep. Everyone pays high tax - even those who do not earn much.
3. U.S. society is built on rugged individualism. Acceptance of immigrants under the premise that they will work hard and contribute. For this reason, U.S. success at integrating immigrants is better than anywhere else in the world, by a wide margin. Our issues re immigration in Europe are numerous and unbelievably contentious. Should the U.S. become a "welfare state," like European countries, it would no longer have a natural filter for immigrants. It would realise the type of immigration that we get in Europe, where for many groups, a majority refuse to work - for life. For this reason, it would require a MUCH tougher filter on immigrants - much more so than what the current administration is doing.
I do not see the U.S. materially reducing spending in other areas, including the military. I do not see general public support for large taxation increases across the board. I do not see public consensus on strict new immigration requirements and enforcement. For these reasons and more, I do not think public health care is a realistic prospect for the foreseeable future.