Health care is a very profitable business.
including medicine, pharmaceuticals, insurance, and all the related and ancillary industries and services associated with it. It is also a rapidly growing industry--all this in an economy otherwise crippled by recession, stagnation and unemployment.
Those who can afford to purchase health care do not want to be taxed to subsidize those who can't.
Those who profit from the existing system, are in no hurry to see anything about it change.
You could say the exact same thing about the firearms industry.