Commentators have focused on the aggressive health-care agendas of Democratic candidates like Bernie Sanders and Elizabeth Warren. Yet of the 20 candidates in last month’s debates, only four said they favored single payer, or Medicare for All. The rest favored a public option—a better approach.

Most Americans want universal coverage but not a radical change tearing up existing plans. Medicare buy-in for nonelderly Americans is an incremental reform that would improve access and lower costs.

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