Going on the offensive and then retreating on busing made Harris seem inauthentic. And the candidate had been dogged by questions of inauthenticity since the start of her campaign because of her waffling on the issue of Medicare for All, the policy at the center of the 2020 Democratic primary.

First Harris indicated at a CNN town hall that she supported abolishing private insurance, as Medicare for All proposes. Then Harris said she didn’t support abolishing private insurance: She tried to hide behind the fig leaf that Medicare for All allows “supplemental insurance,” while obscuring the fact that “supplemental coverage” would be legal for only a very small number of treatments not covered by Medicare for All, such as cosmetic surgery. And cosmetic-surgery insurance doesn’t even exist.

Harris thought she’d finally figured a way out of the Medicare for All mess in July: She introduced her own plan shortly before the Democratic debates. It tried to split the difference: She promised to transition to a single-payer plan in 10 years (as opposed to Sanders’s four-year deadline). This was meant to reassure progressives that they’ll get there eventually while also reassuring moderates that there will be at least two more presidential elections before the country goes through with anything crazy.

Harris’s provision of Medicare Advantage–type plans was also supposed to reassure moderates, but the second debate demonstrated that she still wasn’t ready to respond to the fact that her plan would eventually abolish existing private health plans for everyone, and she has no serious plan for how to pay for single-payer.