Do you know someone misguided enough to want single payer health care for all Americans? If so, you might remind them that the Veterans Administration runs a single payer system for vets.
Ask them if they'd enjoy those conditions, which are very similar to National Health Service facilities in the U.K. Some like that it seems cheap, mostly those too poor to pay income taxes. Many do not care for the quality of service.
Imagine getting your health care delivered by a Department of Motor Vehicles-style bureaucracy understaffed by bored people with don't-give-a-sh*t attitudes. Just what you want when sick and miserable anyway, right?