Right, and states are free to enact single-payer/universal health care for their residents if they so wish. In fact, you might want to look at the Massachusetts health care system.

But implementation at a state level is obviously not what this thread is about.

For a US-wide health care system you need US-wide infrastructure/bureaucracy. This decreases efficiency.

I'm down with this -- this is how Canada's system is run. Each province provides insurance for its residents meeting the requirement to provide a socalized system as defined in the Canada Health Act. States should provide the socialized system, the federal government should mandate a public option exists (either single payer or two-tier) and the basic rules that govern one.