Several years ago, the State of Oregon elected a physician as Governor. He (Dr. Kitzhaber) managed to convince the state legislature to pass a "public option" to cover health insurance for the poor and uninsured. Oregon has one of the strongest anti-tax organizations in the country, and no state income tax, thus state funds were scarce, even before the recession.
At statewide meetings, citizens voted to establish their priorities among medical and surgical treatments, and a final list was compiled. Then treatments on the list were covered by this State program, according to their priority, as funds would allow.
A similar program could be established nationally, with the priority list determined by the Institute of Medicine, the CDC, or another appropriate agency. Medicaid could be included, as well, and an opt in/out provision could be added, if necessary. The cost of such a program might be no higher than the current cost of care of the uninsured in emergency rooms and hospitals.
An obvious criticism could be made that this plan would promote "two-tier medicine". But I would argue that we currently have two (or more) tiers of medical care in this country, and that any tier is better that no tier.