One of the goals of the National Party in the 90's was to move New Zealand towards a more American style of healthcare, cutting public provision and running down the public health system in an effort to force people to go private or get health insurance. It's a goal they still retain today, though they seem to have got it into their skulls that it will never fly with the public, and so have switched the focus to enriching their donors in other ways instead.
As for why we should never consider a US-style healthcare system here, we have only to look at the results of a study by Ellen Nolte and C. Martin McKee of the London School of Hygiene and Tropical Medicine, "Measuring The Health Of Nations: Updating An Earlier Analysis" (abstract, summary). This found that the US was last among rich nations in deaths from treataable disease (meaning their death rates were higher), and improving at a much slower rate (4% over 5 years vs an average of 17% across the 18 countries studied). The difference translates to an estimated 101,000 deaths per year which would be avoided if the US health system was as good as France's, Japan's, or Australia's (or, as Jerome put it, each year, 101,000 Americans die needlessly because they're not French).
Alternatively, we could simply look at bang per buck. The US spends more on healthcare than any other country, and yet ranks poorly amongst developed nations on basic indicators such as life expectancy, and infant mortality. And the reason is the inflated cost of private provision. The lesson is simple: if you want an efficient, effective health system which benefits the public rather than shareholders, you need strong public provision.
