"Like auto insurance (everyone is required to have it by law)"
Only people who choose to become licensed to operate a motorized vehicle on a public roadway, and then proceed to do so, are required to obtain auto insurance. That's a pretty defining requisite, is voluntary, and it certainly isn't "everyone".
So what is the defining requisite that we voluntarily chose to partake in that nessecitates the need for health insurance?
Also, I can't speak for all states, but pretty sure the only required auto insurance, doesn't cover you, just the damage you cause to somebody else.