I don't know why Bernie doesn't bring out the fact that there are already 52 million people in this country that have single payer. It's called Medicare. And it covers the most expensive people in our country. Old Farts and the disabled.
If we can afford to cover them, we can certainly afford to cover the younger non disabled. Especially when we eliminate the blood sucking middlemen Insurance Companies.
http://www.ncpssm.org/Medicare/MedicareFastFacts