For propaganda purposes, the GOP has distorted the meaning of the word socialism to the point that, before we can answer this question, we need to clarify what socialism means. Socialism is an economic system where the government owns the means of production and distribution of the wealth. So universal healthcare and socialized medicine are two different thing.
Aside from the USA, all the developed nations and many in the third world have a universal healthcare system. In nearly all of these nations, healthcare delivers is not socialized, just the the healthcare insurance, which is a single-payer system, is provided by the government with taxpayer support. The doctors, clinics and hospitals all remain private enterprise, hence it is not socialized medicine. The UK does have a socialized medical care system, with hospitals and clinics owned by the government; and doctors and nurses being on the government payroll.
Our US healthcare system is the most expensive in the world. The cost per covered citizen is almost 2 times what the world’s next costliest system runs. The World Heath Organization rated healthcare systems around the world based on healthcare outcomes. They looked at life expectancy, deaths from preventable causes, deaths in childbirth and infant mortality. France is #1 in the world, with a cost per covered citizen almost half that of the US. We are at the very bottom of the developed world in healthcare outcomes at #37, just behind Costa Rica and just above Slovenia.
Now, if you are wealthy, you can BUY the best healthcare on Earth in America. But if you can’t bribe your way to the head of the line, lord help you if you’re sick in America. Nobody else is going to.