Why can’t single-payer and private insurance co-exist?

[SInNYC]

They can co-exist if private insurance is for non-basics. But it gets really dicey if everybody gets to choose between Medicare and a private option since its much too easy for all the expensive cases to choose Medicare. Rules would have to be made to avoid shunting off the expensive cases to Medicare and complicated rules always lead to complicated loopholes.

BTW, people already have no choice. If your employer has health insurance, odds are that you are required to enroll in the plan unless you are in a spouse's plan. But those complaining about being forced to use Medicare dont complain about this for some reason.

[SInNYC]

American politics is too corrupt for option 3. Until corporate personhood is repealed and campaign finance is reformed (and not overruled by the Supreme Court), option 3 or at least the "highly regulated" part of it is not a serious option.