> It thus makes no sense to reject single-payer on the grounds that it would require higher tax revenues. That’s true, of course, but it’s an irrelevant objection.

> The most important source of cost savings under single-payer is that large government entities are able to negotiate much more favorable terms with service providers.

I agree these objections are not relevant for the overall system. But certain individuals and groups within the current system will get screwed.

The wealthy and upper middle-class will oppose any tax increases, as it will decrease their take-home income. Plus the resentment of having to pay for someone else (the moochers).

Providers will oppose any haircut that comes with single-payer rates and price controls. No more millionaire doctors, specialists, or dentists.

And of course the overhead of health insurance middle-men and the huge administrative bureaucracy costs.

This is the crux of the problem. We could have a reasonably good system for everyone. But it requires a lot of people with heavily vested interests into a less ideal situation.