Mathew Continetti writes at National Review Online about the negative political impact of supporting “Medicare for all” proposals.

Yes, it helps to have a reason for your candidacy beyond media reports that you check all the right boxes. But the argument that [Kamala] Harris flopped because of a failure to communicate lets her off easy.

The Times piece didn’t mention the policy initiative upon which Harris launched her campaign: Bernie Sanders’s Medicare-for-All legislation, which would eliminate private and employer-based health insurance. Harris signed on as a cosponsor to the bill last April. It’s haunted her ever since. Medicare for All might look like the sort of “big, structural change” that sets progressive hearts aflutter. For most voters it causes arrhythmia.

The proposal is liberals’ fool’s gold. It appears valuable but is actually worthless. It gets the progressive politician coming and going: Not only do voters recoil at the notion of having their insurance canceled, but candidates look awkward and inauthentic when they begin to move away from the unpopular idea they mistakenly embraced. That’s what happened to Harris earlier this year and is happening to Elizabeth Warren today.

Harris moved into second place nationwide after her ambush of Joe Biden over busing during the first Democratic debate. But her position soon began to erode. Her wavering position on eliminating private insurance dissatisfied voters. She had raised her hand in support of the policy during the debate, but the next day she walked it back. Then she walked back the walk-back.