"I do think that there is a danger that if the US moved to a social medicine system, that the engine of research, the profits derived from the medical industry, would stall and we would see fewer medical breakthroughs."

On the contrary: medicine would be paid for by the state, so more people would have access to it, so the companies would be able to sell more instead of limiting their market to people who can afford it with their own means.

Of course if a "social medicine system" meant control of the industry by the state, as in some form of communist economy, you would be right, but that's not what a national health system is about.