For thousands of years, the question of healthcare has been basically irrelevant. If you got seriously ill, your death or survival — usually the former — had little to do with how much care you received, and it didn’t matter if you were the King of England or an American slave. People may have thought healthcare was important, but it didn’t really matter; environmental factors such as general health and diet, shelter, and workload mattered much more. To put it in perspective, most of us can count how many times we would have already died had we lived 150 years ago. For me, the score is two: I’ve had appendicitis and bacterial pneumonia so bad I was coughing blood. Neither was tremendously problematic or fearsome.

Because we’ve made such remarkable progress, healthcare matters. That progress is broadly the result of two things. The first is evidence-based medicine. In the late 1800s, somebody did a study and realized that outcomes were no better if you went to a doctor for treatment. That didn’t speak well for doctors. More recent studies have shown the same thing for Medicaid: outcomes are better for people who are totally uninsured rather than for those on Medicaid.