Just going by personal interest, I should be wildly in favor of universal health insurance. But as to the country at large, I worry about the rationing issue.
To be clear, I'm not worried that there will be too much rationing, I'm worried that there won't be enough. For a wide variety of reasons, I'm suspicious of the value of a lot of so-called "healthcare." Healthcare (not the lack of it) is one of the leading causes of death
in America (doctor error, risks of surgery, hospital-borne infections, etc., etc.). And many treatments
lack valid evidence that they even work.
Will there be enough rationing in a universal system? Probably not. Many people are frantic that there might be rationing (in the form of a refusal to pay for any requested service whatsoever), and the response of liberals is usually to proclaim that there will be less rationing under a government program than in the private market. So both sides will be on board for trying to limit rationing.
Thus, a universal system in America would, thanks to the political forces at work, serve to increase the total amount of healthcare consumed. Even though some people would benefit from more healthcare, that wouldn't be an average effect: lots of people would be harmed by having more healthcare. Thus, the American population would probably become less healthier on average, while paying more.
Not a good deal. There's got to be a better way to subsidize catastrophic insurance for the means-tested portion of the population that is most likely to need help there.