The main reason health care costs are skyrocketing is that so many pay for health care through 3rd party payers (ie insurance companies and the govt). If you can pay 20 cents for every dollar worth of medical care then you are going to want a lot of it. That is why premiums continue to rise and why HMOs came along in the first place. The reason why most people have gotten health care insurance through their employers is because during WWII employers started providing health benefits to employees to get around the price controls which were in place at the time. Then the IRS ruled that the value of such benefits were not taxable for the employee. Workers started to expect those benefits and yet the cost of those benefits started to increase significantly as insurance companies had to raise premiums to keep up with the cost of the claims. Hence the advent of the HMO, which employed some rationing methods in order to keep the cost of the premiums low. A lot of people hate HMOs because of that rationing. A government takeover of health care would create the largest HMO in the history of mankind.
We should move back to insurance being used for high cost, relatively low probability events such as major surgeries and extended treatment and hospital stays for severe illnesses. The government can provide assistance to those lower income individuals and families who can't afford the premiums. As for routine expenses such as doctor visits and drug prescriptions for individuals, that's where medical IRAs enter the picture. And again, for those who need assistance because they can't afford to pay for it, the government can provide that assistance.
As for the bargaining power of health insurance companies versus drug companies, I'd say some insurers are rather large enough to bargain effectively with them and I'd also point to the track record of federal government agencies such as the Department of Defense when it comes to negotiating deals with private contractors. It's also a situation ripe for political corruption. The US being the global leader when it comes to medical innovation and research. That is driven by the fact that our health care industry is still market driven and the returns are there to attract the investment which leads to those new discoveries. That is directly at risk the more we increase the government's role in the health care industry.
This is not to say that the Bush administration is the font of all wisdom, for there is plenty of fiscal and monetary matters on which I am considerably less than enthused with what he has done.
The gist of what I am saying is that the best way to proceed is to keep the health care market a free market with the government's role being to provide financial assistance to those who cannot afford to pay for the routine care or the catastrophic health care insurance premiums, but not to create a mammoth insurance program in which everyone is coerced into it due to the fact that they are being taxed to pay for it. I'd also say this is the preferable model when it comes to other industries in which the federal, state, and local governments are involved heavily, such as K-12 education.