As the next major Democratic bill makes its way through Congress, there will likely be a fight about whether Democratic health care reform should take the form of expanding subsidies for individuals receiving insurance on the ACA exchanges or take the form of expanding access to Medicare, such as through lowering the Medicare eligibility age.

These kinds of debates are often seen as proxy debates between Democratic factions that are proud of Obamacare and Democratic factions that have been disappointed or embarrassed by it. Since Obamacare has become associated with the ACA exchanges more than anything else, the former group seem especially fixated on those exchanges even though they enroll relatively few people. And since opponents of Obamacare tend to prefer Medicare for All, they tend to fixate on ways to expand Medicare.

What’s unfortunately missing in this debate is a reality check about what Obamacare actually did. Between 2010 and 2019, the rate of uninsurance fell from 15.6 percent to 9.2 percent, a significant accomplishment. But this drop was almost entirely driven by expansions of Medicare and Medicaid. Expansions in non-group coverage (which is what the ACA exchanges are) only account for 9 percent of the insurance gains over the period.

The ACA’s Medicaid expansions obviously explain its contribution to the uninsurance drop. The Medicare increase is less obvious, but was probably driven by the fact that the share of the population old enough to receive Medicare increased substantially over the period.

In a sense, then, the Obamacare partisans that fixate on the ACA exchanges are engaged in a kind of fetishism that really has little to do with what Obamacare accomplished. Anyone looking clearly at Obamacare’s track record would conclude that it caused and coincided with a significant expansion of public health insurance that helped reduce uninsurance. If you were trying to build on actually-existing Obamacare, then you’d focus on its relatively successful legacy of expanding public health programs, not its relatively failed legacy of building an individual health insurance market.