1. Why is medical care the highest priority? What about food? Shelter? Safety from rape, murder, and other forms of violence? What about electricity, water, and other infrastructure? While most people don't get very sick, pretty much everyone needs the things above. Why should medical care be the highest priority federal expense?
2. You think it's barbaric to think about paying for medical care, but guess what: you do pay for it. Everyone does. Your "right" to healthcare is not free; someone has to pay for it. And because you think you're entitled to that free of charge, someone else out there is having money taken from them under the threat of force so that you don't have to worry about healthcare. The right to private property far outweighs the right to healthcare, according to the US Constitution, but your system reverses this relationship.
3. The decoupling of supply and demand in the type of system we're about to pass is likely to result in dramatically higher costs and lower quality care over the long run, not to mention the fact that we have no way of paying for it. Granted, our current system is screwed up, but this is far from a fix. This is just moving further in a bad direction.
EDIT: Added a third item :)