Michael Tanner uses his latest National Review Online column to highlight health care challenges that politicians can’t wish away.

[W]hoever eventually comes up with a replacement for the Affordable Care Act should keep a few hard truths in mind.

1. Health care is neither a right nor a privilege; it’s a commodity. Worse, it’s a finite commodity. There are only so many doctors, so many hospitals, and so much money, and there are limits to how much these things can be expanded. That’s why no health-care system, outside Bernie Sanders’s fantasies, provides unlimited care to everyone.

Every health-care system in the world rations care in some way, either through bureaucratic fiat (Scandinavia, the U.K.), waiting lists (Canada), or price (that’s us). One can argue about which of these rationing mechanisms is fairest or most efficient, but let’s not pretend that it won’t occur.

2. Coverage is not access. Democrats like to pretend that giving everyone a piece of paper called insurance guarantees them access to the care they need. It’s sort of like magic. Say the right words, and poof, medical care appears. But in the real world it doesn’t work that way. …

… 3. The uninsurable are uninsurable. Let us remember that the definition of “pre-existing condition” is: someone who is already sick. It’s a little like driving your car into a tree and then trying to retroactively buy auto insurance. It won’t work. Insurance is the business of spreading risk. But for someone who, say, has cancer, there’s no risk to spread, just cost. That’s not insurance, it’s paying for health care.

Obamacare tried to square this circle by mandating that young and healthy people buy insurance to offset the cost of providing care to those already sick. It turns out that didn’t work. Not enough healthy people signed up to pay for the influx of sick people. Insurance companies either dropped out of the market, cut back on high-quality providers, or raised premiums. All of this forced more healthy people out of the insurance pool and threatened an adverse-selection death spiral.