Dennis
A single payer is a monopoly. That generally means high cost since there is no competition to drive down costs. Our Canadian system is an excellent example, costs are out of control. 

With so many years of discouraging or even prosecuting monopolies, why do you think it can work in health care?

All the US needs is to remove health care legislation and legislate a Guaranteed Annual income for the poor. It gives the poor access to the best medical system in the world - probably one reason for high cost.