In the UK, the NHS was strongly resisted by the BMA (doctor's union basically) in order to get the deal done the Minister of Health, in his own words, had "stuffed their mouths with gold".

At roughly the same time in the US, the current mania about socialized medicine equaling death panels and communism got started with spin doctors hired by the doctor's unions. In fact Wikipedia tells me that the actual phrase "socialized medicine" was "first widely used in the United States by advocates of the American Medical Association in opposition to President Harry S. Truman's 1947 health-care initiative."

The article "The Lie Factory: How politics became a business" gives some interesting historical insight into this:

http://www.newyorker.com/reporting/2012/09/24/120924fa_fact_...

They continue to lobby against these reforms to this day, more from Wikipedia:

"The AMA has one of the largest political lobbying budgets of any organization in the United States.[6] Its political positions throughout its history have often been controversial. In the 1930s, the AMA attempted to prohibit its members from working for the then-primitive health maintenance organizations that had sprung up during the Great Depression, which violated the Sherman Antitrust Act and resulted in a conviction ultimately affirmed by the US Supreme Court.[7] The AMA's vehement campaign against Medicare in the 1950s and 1960s included the Operation Coffee Cup supported by Ronald Reagan. Since the enactment of Medicare, the AMA reversed its position and now opposes any "cut to Medicare funding or shift [of] increased costs to beneficiaries at the expense of the quality or accessibility of care". However, the AMA remains opposed to any single-payer health care plan that might enact a National Health Service in the United States, such as the United States National Health Care Act. In the 1990s, the organization was part of the coalition that defeated the health care reform advanced by Hillary and Bill Clinton."

They also to fight to protect their status, and prevent nurses, pharmacists and other less-credentialled healthcare workers from performing roles that they could do just as well (if not better) and at cheaper cost. Relevantly for the tech-nerd contingent here (if raising the cost and reducing the quality of health care wasn't already relevant enough), they're probably going to fight expert systems that threaten their turf too (if they haven't already started to) just like car dealers vs Tesla motors.

Here's randomly Googled article on them fighting against an expanded role for Nurses:

http://takingnote.tcf.org/2010/04/the-battle-over-letting-nu...

"The American Medical Association (AMA) represents many members of the old guard, and is intent on protecting the guild. In some statehouses, the Associated Press (AP) reports: “Doctors have shown up in white coats to testify against nurse practitioner bills. The AMA, which supported the national health care overhaul, says that a doctor should supervise an NP at all times and in all settings. Just because there is a doctor shortage, the AMA argues, is no reason to put nurses in charge and endanger patients.”

But others argue that Nurse Practitioners have the needed training and that, in fact, doctors who have gone through the full medical school curriculum are over-qualified for a job that, today, is more about coordinating care than medical science."