The Federal Government already acts as the purchasing agent for its citizens in a number of important transactions. The best example is the US military.
Currently, the Pentagon consumes at least $534 billion of your tax dollars. It's always been the big eater in the federal budget. Has anyone called it "socialized defense?" Hell, no. Even though the military services are in fact socialist societies, no one makes much of a time about that. And that's not the critical factor here. What matters is the way government expenditure interacts with the private sector.
No one can claim that government funding and involvement has stifled innovation or decreased profitability in the area of inventing exciting ways to devastate enemy nations. Quite the contrary. Competing for competitive bids, the military-industrial complex has supplied an endless stream of guns, bombs, missiles, tanks, aircraft that don't show up on radar, shrapnel that doesn't show up on X-rays, stuff with computers, lasers, gas, germs and trained dolphins. Why should the response of the medical industries be any more restrained?
By making the government our negotiator and purchaser of medical supplies and services, we put the full power of the treasury to work for us. Hey, we put that money there! Let's get something back.
Private insurance is a mortally wounded business. They're shot, they just haven't fallen down yet. Here's why: a service provider can only be profitable if they can reasonably estimate their costs. Sickness does not succumb to the same statistical modeling as death, for instance. The stakes are higher. A policy holder could become expensively ill. The cost effective thing to do with someone who has started costing more than they're bringing in is to lay them off. Private insurers hire legions of phone operators to try to hold back all but the most determined petitioners who have been denied. It's frustrating and expensive for all concerned. Putting them out of this dead-end business would only be merciful. Euthanize the private health insurance companies! They'll find someplace else to invest their money! Corporations have diversified and evolved forever. If they're so crappy at business that they can't weather a complete market shift like that, we don't want them managing something as important as health care anyway.
There is no need to fear a non-profit, public funding source that will act the way insurance began: as a shared risk pool in which everyone pays a share and gets only such recompense from it as they actually need. We're not furnishing someone's corporate suite, paying for their private jet or funding their weekend in Vegas. With a public, non-profit health insurance system, we're paying for health care, period. As a government entity, it HAS to operate under full disclosure (nothing classified in health care, UNLIKE the military). We get to look at the books whenever we want. When was the last time (or even the first) that a private insurance company invited you to do that?
The government can be frustrating to deal with. Just remember that it is your government. Take some interest beyond simply voting in the Candy Man and then throwing him out when he isn't perfect. We have laws that give us tremendous access to what goes on in domestic affairs. It isn't perfect, but nothing is. And it isn't socialism. It's our shared business venture as shareholders in the United States. Let's build it right and make it work. We owe it to our investors.