alt Hacker NewsSwitzerland uses a system similar to the original plan for Obamacare, where individuals are mandated to buy insurance, so if Switzerland is what you mean by "universal healthcare" then it's not only not impossible, but the USA already has a more voluntary take on the exact same concept.
The ACA has been steadily kneecapped since its inception.
And the “more voluntary” bit is pretty important. As is it costing about double.