Those who believe that the government should provide everybody with free healthcare have long struggled with a way to brand it. The term socialized health insurance has a negative connotation and “single-payer healthcare” is too wonky. So in recent years, activists have pushed leading Democrats to adopt the term “Medicare for all.”

The “Medicare for all” branding allows activists to latch onto a program that remains broadly popular. It will be an easier lift, liberals presume, if they can convince everybody that they just want to build on something that Americans already know and like. Because the term “Medicare for all” means different things to different people, it can allow politicians to claim support for it without alienating one group or another. But an increasing amount of polling data show that the vague promise of “Medicare for all” is creating a lot of confusion — even among Democratic voters.